I am trying to connect an iPhone 16 (iOS 18.3) to a Wi-Fi device with the SSID "DIRECT-DR_6930_KP201128", but every time, without being able to enter the Wi-Fi password, the message "Unable to join the network 'DIRECT-DR_6930_KP201128'" is displayed. Below are the system logs from the connection failure. Could you please tell me the cause of the connection failure? By the way, an iPhone SE 2nd (iOS 18.2.1) can connect to the same Wi-Fi device without any issues. System Logs: ・Jan 31 19:18:14 900-iPhone-16-docomo Preferences(WiFiKit)[351] : {ASSOC-} association finished for DIRECT-DR_6930_KP201128 - success 0 ・Jan 31 19:18:14 900-iPhone-16-docomo runningboardd(RunningBoard)[33] : Assertion 33-351-4412 (target:[app<com.apple.Preferences(DE1AB487-615D-473C-A8D6-EAEF07337B18)>:351]) will be created as inactive as start-time-defining assertions exist ・Jan 31 19:18:14 900-iPhone-16-docomo Preferences(WiFiKit)[351] : association failure: (error Error Domain=com.apple.wifikit.error Code=12 "Unknown Error" UserInfo={NSDebugDescription=Unknown Error, NSUnderlyingError=0x303307660 {Error　Domain=com.apple.corewifi.error.wifid Code=-3938 "(null)"}}) ・Jan 31 19:18:14 900-iPhone-16-docomo Preferences(WiFiKit)[351] : dismissing credentials view controller for DIRECT-DR_6930_KP201128

In our App, we have a network extension with a NEAppPushProvider subclass running. We run the following steps Setup a dual-band wireless router per the following: Broadcasting 2.4 GHz and 5 GHz channels Same SSID names for both channels Connected to the production network to the router DHCP assigning addresses in the 10.1.x.x network Connect the mobile device to the 5 GHz network (if needed, turn off the 2.4 GHz network temporarily; once the device connects to the 5 GHz network, the 2.4 GHz network can be turned back on). Create a NEAppPushManager in the App, using the SSID from the above mentioned network and set it to the matchSSIDs property. Call saveToPreferences() on the push manager to save. A. We have UI that shows the extension has been started and it has connected to the server successfully. Walk out of the range of the 5 GHz channel of the router, but stay within range of the 2.4ghz channel. Wait for the mobile device to connect to the 2.4 GHz channel. Expected: The extension would reconnect to the 2.4ghz network. Observed: The extension does not reconnect. Checking the logs for the extension we see that the following was called in the push provider subclass. stop(with:completionHandler:) > PID: 808 | 🗒️🛑 Stopped with reason 3: "noNetworkAvailable" The expectation is that start() on the NEAppPushProvider subclass would be called. Is this an incorrect expectation? How does the NEAppPushProvider handle same network SSID roaming among various band frequencies? I looked at the documentation and did not find any settings targeting 2.4 or 5 ghz networks. Please advise on what to do.

I have some concerns related to shortening the lifetime of certificates, as per https://support.apple.com/en-gb/102028 Does this apply to Private CA root certificates? And if yes: does it apply if I use ATS and higher level API like URLSession does it apply it I carry my root CA cert in my app payload and use low level libraries without ATS support?

Recently, my application was having trouble sending udp messages after it was reinstalled. The cause of the problem was initially that I did not grant local network permissions when I reinstalled, I was aware of the problem, so udp worked fine after I granted permissions. However, the next time I repeat the previous operation, I also do not grant local network permissions, and then turn it back on in the Settings, and udp does not work properly (no messages can be sent, the system version and code have not changed). Fortunately, udp worked after rebooting the phone, and more importantly, I was able to repeat the problem many times. So I want to know if the process between when I re-uninstall the app and deny local network permissions, and when I turn it back on in Settings, is that permissions have been granted normally, and not fake, and not required a reboot to reset something for udp to take effect. I'm not sure if it's the system, or if it's a similar situation as described here, hopefully that will help me find out

I have been battling this intermittent error for some time. It is generally random and has been difficult to reproduce until yesterday when I stumbled across a way to reproduce it each time. I can cause the code to throw this error: Task <70E3909F-8C30-4F34-A8B0-4AF3B41DD81B>.<1> finished with error [-1001] Error Domain=NSURLErrorDomain Code=-1001 "The request timed out." UserInfo={_kCFStreamErrorCodeKey=-2103, _NSURLErrorFailingURLSessionTaskErrorKey=BackgroundDownloadTask <70E3909F-8C30-4F34-A8B0-4AF3B41DD81B>.<1>, _NSURLErrorRelatedURLSessionTaskErrorKey=( "BackgroundDownloadTask <70E3909F-8C30-4F34-A8B0-4AF3B41DD81B>.<1>", "LocalDownloadTask <70E3909F-8C30-4F34-A8B0-4AF3B41DD81B>.<1>" ), NSLocalizedDescription=The request timed out., _kCFStreamErrorDomainKey=4, NSErrorFailingURLStringKey=https://redacted*, NSErrorFailingURLKey=https://redacted*} *"redacted" is the backend URL, and it is the correct and same path for each immediately after restarting an actual device. I have been over the following threads with no results: What is kCFStreamErrorCodeKey=-4 (kCFStreamErrorDomainKey=4) Request timed out with _kCFStreamErrorCodeKey=60 How to better diagnose -1001 "The request timed out." URLSession errors Random timed out error on app start Because I was able to reproduce it, I have been able to get the following logs: Console Logs.txt Last bit of information is that I had Network Instruments running, and when this error occurred, I found that the Connection ID was "No Connection" and it appears the request was never actually sent, though it waited the full time out for a backend response. Any help would be appreciated. This data request is being used after sending a certain APNs to update necessary data in the background, and has been the source of many user complaints.

Question 1: After NetworkExtension is installed, when the software receives a pushed uninstall command, it needs to download the entire software but fails to uninstall this NetworkExtension. Are there any solutions? Question 2: How can residual, uninstalled NetworkExtensions be cleaned up when SIP (System Integrity Protection) is enabled?

Hi, I’m using Network Framework to implement a UDP client via NWConnection, and I’m looking for clarification about the correct and fully safe shutdown procedure, especially regarding resource release. I have initiated some pending receive calls on the NWConnection (using receive). After calling connection.cancel(), do we need to wait for the cancellation of these pending receives? As mentioned in this thread, NWConnection retains references to the receive closures and releases them once they are called. If a receive closure holds a reference to the NWConnection itself, do we need to wait for these closures to be called to avoid memory leaks? Or, if there are no such retained references, we don't need to wait for the cancellation of the pending I/O and cancelled state for NWConnection?

Summary NetworkConnection<WebSocket> in iOS 26 Network framework throws POSIXErrorCode(rawValue: 22): Invalid argument when receiving WebSocket ping (opcode 9) or pong (opcode 10) control frames. This prevents proper WebSocket keep-alive functionality. Environment iOS 26.0 (Simulator) macOS 26.1 Xcode 26.0 Note: This issue was initially discovered on iOS 26 Simulator. The same behavior was confirmed on macOS 26, suggesting a shared bug in the Network framework. The attached sample code is for macOS for easier reproduction. Description When using the new NetworkConnection<WebSocket> API introduced in iOS 26 or macOS 26, the receive() method throws EINVAL error whenever a ping or pong control frame is received from the server. This is a critical issue because: WebSocket servers commonly send ping frames to keep connections alive Clients send ping frames to verify connection health The receive callback never receives the ping/pong frame - the error occurs before the frame reaches user code Steps to Reproduce Create a WebSocket connection to any server that supports ping/pong (e.g., wss://echo.websocket.org): import Foundation import Network // MARK: - WebSocket Ping/Pong EINVAL Bug Reproduction // This sample demonstrates that NetworkConnection<WebSocket> throws EINVAL // when receiving ping or pong control frames. @main struct WebSocketPingPongBug { static func main() async { print("=== WebSocket Ping/Pong EINVAL Bug Reproduction ===\n") do { try await testPingPong() } catch { print("Test failed with error: \(error)") } } static func testPingPong() async throws { let host = "echo.websocket.org" let port: UInt16 = 443 print("Connecting to wss://\(host)...") let endpoint = NWEndpoint.hostPort( host: NWEndpoint.Host(host), port: NWEndpoint.Port(rawValue: port)! ) try await withNetworkConnection(to: endpoint, using: { WebSocket { TLS { TCP() } } }) { connection in print("Connected!\n") // Start receive loop in background let receiveTask = Task { var messageCount = 0 while !Task.isCancelled { do { let (data, metadata) = try await connection.receive() messageCount += 1 print("[\(messageCount)] Received frame - opcode: \(metadata.opcode)") if let text = String(data: data, encoding: .utf8) { print("[\(messageCount)] Content: \(text)") } else { print("[\(messageCount)] Binary data: \(data.count) bytes") } } catch let error as NWError { if case .posix(let code) = error, code == .EINVAL { print("❌ EINVAL error occurred! (POSIXErrorCode 22: Invalid argument)") print(" This is the bug - ping/pong frame caused EINVAL") // Continue to demonstrate workaround continue } print("Receive error: \(error)") break } catch { print("Receive error: \(error)") break } } } // Wait for initial message from server try await Task.sleep(for: .seconds(2)) // Test 1: Send text message (should work) print("\n--- Test 1: Sending text message ---") try await connection.send("Hello, WebSocket!") print("✅ Text message sent") try await Task.sleep(for: .seconds(1)) // Test 2: Send ping (pong response will cause EINVAL) print("\n--- Test 2: Sending ping frame ---") print("Expecting EINVAL when pong is received...") let pingMetadata = NWProtocolWebSocket.Metadata(opcode: .ping) try await connection.ping(Data()) { pingMetadata } print("✅ Ping sent, waiting for pong...") // Wait for pong response try await Task.sleep(for: .seconds(2)) // Cleanup receiveTask.cancel() print("\n=== Test Complete ===") print("If you saw 'EINVAL error occurred!' above, the bug is reproduced.") } } } The receive() call fails with error when pong arrives: ❌ EINVAL error occurred! (POSIXErrorCode 22: Invalid argument) Test Results Scenario Result Send/receive text (opcode 1) ✅ OK Client sends ping, receives pong ❌ EINVAL on pong receive Expected Behavior The receive() method should successfully return ping and pong frames, or at minimum, handle them internally without throwing an error. The autoReplyPing option should allow automatic pong responses without disrupting the receive loop. Actual Behavior When a ping or pong control frame is received: The receive() method throws NWError.posix(.EINVAL) The frame never reaches user code (no opcode check is possible) The connection remains valid, but the receive loop is interrupted Workaround Catch the EINVAL error and restart the receive loop: while !Task.isCancelled { do { let received = try await connection.receive() // Process message } catch let error as NWError { if case .posix(let code) = error, code == .EINVAL { // Control frame caused EINVAL, continue receiving continue } throw error } } This workaround allows continued operation but: Cannot distinguish between ping-related EINVAL and other EINVAL errors Cannot access the ping/pong frame content Cannot implement custom ping/pong handling Impact WebSocket connections to servers that send periodic pings will experience repeated EINVAL errors Applications must implement workarounds that may mask other legitimate errors Additional Information Packet capture confirms ping/pong frames are correctly transmitted at the network level The error occurs in the Network framework's internal processing, before reaching user code

hello I am testing the use of network extension. When we use dnsproxy to proxy DNS requests, we will send you a message that the udp pcbcount of your system continues to increase. For example for ((i=1; i<=99999; i++));do echo "Attempt $i:" dig google.com done when the dig command is used continuously, the dig command will show the following errors when pcbcount reaches a certain number. isc_socket_bind: address not available Can you help us determine what the problem might be? thank you

I have read all the information and forum posts about local network, such as TN3179, etc., and have added NSLocalNetworkUsageDescription, but it does not solve my problem. The problem I encountered is described as follows: Device: iOS18.1.1 Signing method: automatic Xcode debug directly runs, and the app can access 17.25.11.128 normally. However, relase run or packaged into adhoc installation, this IP cannot be accessed. There is a phenomenon that the app package of the App Store can also be used. Our test team has few iOS18+ devices, and internal testing is not possible. Please contact us as soon as possible, thank you. ======= 我已经了解了所有关于local network 相关的资料和论坛帖子，比如TN3179 等等， 已经添加了 NSLocalNetworkUsageDescription， 但是不解决我的问题。 我遇到的问题描述如下： 设备：iOS18.1.1 签名方式：自动 xcode debug 直接运行，app是可以正常访问17.25.11.128的。 但是 relase run 或者 打包成 adhoc 安装，就无法访问这个IP了。 有一个现象， App Store 的app包 也是可以的。 我们的测试团队，iOS18+的设备就没几个，还不能内部测试了。请尽快联系我们，谢谢。

I'm struggling to understand why the async-await version of URLSession download task APIs do not call the delegate functions, whereas the old non-async version that returns a reference to the download task works just fine. Here is my sample code: class DownloadDelegate: NSObject, URLSessionDownloadDelegate { func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) { // This only prints the percentage of the download progress. let calculatedProgress = Float(totalBytesWritten) / Float(totalBytesExpectedToWrite) let formatter = NumberFormatter() formatter.numberStyle = .percent print(formatter.string(from: NSNumber(value: calculatedProgress))!) } } // Here's the VC. final class DownloadsViewController: UIViewController { private let url = URL(string: "https://pixabay.com/get/g0b9fa2936ff6a5078ea607398665e8151fc0c10df7db5c093e543314b883755ecd43eda2b7b5178a7e613a35541be6486885fb4a55d0777ba949aedccc807d8c_1280.jpg")! private let delegate = DownloadDelegate() private lazy var session = URLSession(configuration: .default, delegate: delegate, delegateQueue: nil) // for the async-await version private var task: Task&lt;Void, Never&gt;? // for the old version private var downloadTask: URLSessionDownloadTask? override func viewWillAppear(_ animated: Bool) { super.viewWillAppear(animated) task?.cancel() task = nil task = Task { let (_, _) = try! await session.download(for: URLRequest(url: url)) self.task = nil } // If I uncomment this, the progress listener delegate function above is called. // downloadTask?.cancel() // downloadTask = nil // downloadTask = session.downloadTask(with: URLRequest(url: url)) // downloadTask?.resume() } } What am I missing here?

We found there is a significant crash reports (most of them are from iOS 17, the rest are iOS 16 and 15) comes from network loader from CFNetwork. Apparently it seems there are two types of crashes if we checked from the stack trace, the one we found from both Xcode organizer and 3rd party crash reporter is referring to URLConnectionLoader::loadWithWhatToDo and the other one from our 3rd party crash reporter (didn’t found the report from Xcode organizer) referring to _CFURLResponseCreateFromArchiveList (this one only happened on iOS 17.5 and later devices). It seems that they are both kinda similar which might point to the same root cause. From what I’ve seen, we never touch the lower level API directly, we usually use the URLSession to manage our API request. The crashed stack trace also didn’t give any indication about which of our app code that triggered the crash, it only shows calls to Apple’s internal SDKs so we are unsure how to approach this issue meanwhile the crash event already reached 800+ in the last 30 days. Unfortunately, we cannot reproduce the issue as the stack trace itself seems unclear to us. I have submitted a report through feedback assistant with number: FB14679252. Would appreciate if anyone can give any advice on what we can do to avoid this in the future and probably any hint on why it could happened. Hereby I attached the crash reports that we found each from Xcode crash report and our 3rd party crash reporter (the report said it crashed on com.apple.CFNetwork.LoaderQ) so you could get a glimpse of the similarity. Xcode crash report xcode crash report.crash 3rd party crash report 3rd party crash report.txt

I’m developing an app designed for hospital environments, where public internet access may not be available. The app includes two components: the main app and a Local Connectivity Extension. Both rely on persistent TCP socket connections to communicate with a local server. We’re observing a recurring issue where the extension’s socket becomes unresponsive every 1–3 hours, but only when the device is on the lock screen, even if the main app remains in the foreground. When the screen is not locked, the connection is stable and no disconnections occur. ❗ Issue Details: • What’s going on: The extension sends a keep-alive ping packet every second, and the server replies with a pong and a system time packet. • The bug: The server stops receiving keep alive packets from the extension.  • On the server, we detect about 30 second gap on the server, a gap that shows no packets were received by the extension. This was confirmed via server logs and Wireshark).  • On the extension, from our logs there was no gap in sending packets. From it’s perspective, all packets were sent with no error.  • Because no packet are being received by the server, no packets will be sent to the extension. Eventually the server closes the connection due to keep-alive timeout.  • FYI we log when the NEAppPushProvider subclass sleeps and it did NOT go to sleep while we were debugging. 🧾 Example Logs: Extension log: 2025-03-24 18:34:48.808 sendKeepAliveRequest() 2025-03-24 18:34:49.717 sendKeepAliveRequest() 2025-03-24 18:34:50.692 sendKeepAliveRequest() ... // continuous sending of the ping packet to the server, no problems here 2025-03-24 18:35:55.063 sendKeepAliveRequest() 2025-03-24 18:35:55.063 keepAliveTimer IS TIME OUT... in CoreService. // this is triggered because we did not receive any packets from the server Server log: 2025-03-24 18:34:16.298 No keep-alive received for 16 seconds... connection ID=95b3... // this shows that there has been no packets being received by the extension ... 2025-03-24 18:34:30.298 Connection timed out on keep-alive. connection ID=95b3... // eventually closes due to no packets being received 2025-03-24 18:34:30.298 Remote Subsystem Disconnected {name=iPhone|Replica-Ext|...} ✅ Observations: • The extension process continues running and logging keep-alive attempts. • However, network traffic stops reaching the server, and no inbound packets are received by the extension. • It looks like the socket becomes silently suspended or frozen, without being properly closed or throwing an error. ❓Questions: • Do you know why this might happen within a Local Connectivity Extension, especially under foreground conditions and locked ? • Is there any known system behavior that might cause the socket to be suspended or blocked in this way after running for a few hours? Any insights or recommendations would be greatly appreciated. Thank you!

Apologies if this is not the correct topic to post under. EpochField 5.2 is our application. It's a .NET MAUI application built against XCode 16. A customer of ours uses another app, TN3270, to connect to a mainframe host. After installing our app on an iPad and restarting the device, the TN3270 app will disconnect when suspended. Uninstalling our app (EpochField) will allow the TN3270 to suspend without disconnecting. We have tried removing background services, setting UIRequiresFullScreen to false or removing it entirely, and several other ideas. The only remedy seems to be uninstalling EpochField. On an iPad device: Install MochaSoft’s TN3270 app (free version is fine). Create a connection to ssl3270.nccourts.org, port 2023, SSL/TLS turned on, keep alive turned on. Verify that you can connect. Suspend the app by swiping up or choosing another app. Go back to TN3270 and verify that the app has not disconnected. Install EpochField 5.2. Do not run or configure the app, just install it. Repeat step 2. Restart the device. Open EpochField 5.2. You do not need to configure the app or login. Sometimes it isn't necessary to ever open EpochField to get the disconnects, but this is the most reliable way to reproduce the situation. Repeat step 2. The TN3270 app will now disconnect when suspended, even if EpochField is closed. You may need to wait a few seconds after suspending. Uninstall EpochField 5.2. Repeat step 2: the TN3270 app will now remain connected when suspended.

I found a problem where a process tries to connect to System Extension and connection is invalidated. XPC listener has to be disposed and initialized again. This happens when System Extension executes tasks in following order: NSXPCListener initialized NSXPCListener.resume() NSProvider.startSystemExtensionMode() Result: Connection is invalidated and not only that the client has to retry connection, nut also System Extension must reinitialize listener (execute step 1 and 2). However if I call NSProvider.startSystemExtensionMode() NSXPCListener initialized NSXPCListener.resume() It works as expected and even if the connection is invalidated/interrupted, client process can always reconnect and no other action is necessary in System Extension (no need to reinitialize XPC listener), In Apple docs about NSProvider.startSystemExtensionMode() it says that this method starts handling request, but in another online article written by Scott Knight I found that startSystemExtensionMode() also starts listener server. Is that right? PLease could you add this info into the docs if it is so? https://knight.sc/reverse%20engineering/2019/08/24/system-extension-internals.html I would like to use following logic: Call NSProvider.startSystemExtensionMode() only under certain circumstances - I have received some configuration that I need to process and do some setup. If I don't receive it, there is no reason to call startSystemExtensionMode() yet, I don't need to handle handleNewFlow() yet. Connect XPC client to System Extension under certain conditions. Ideally communicate with client even though System Extension is not handling network requests yet, that is without receiving handleNewFlow(). Basically I consider XPC and System Extension handling network requests as separate things. Is that correct, are they separate and independent? Does XPC communication really depend on calling startSystemExtensionMode()? Another potential issue: Is it possible that XPC listener fails to validate connection when client tries to connect before System Extension manages to complete init and park the main thread in CFRunLoop? Note: These querstions arose mostly from handling upgrades of System Extension (extension is already running, network filter is created and is connected and new version of the app upgrades System Exension). Thanks.

Hey, We also opened a feedback assistant request, and also opened a ticket with Apple Developer Technical Support a while ago that notice the unmount problem also but it was before we pin point the problem to the Network Extension. After a further investigation, we've found out that the root cause of this problem is cause by having a network filter from the NetworkExtension provider on (Specifically we have tested with the NEFilterDataProvider) while having a Xsan volume. The NEFilterDataProvider causing problems for the Xsan, and is stalling the shutdown until we get a panic from watchdog timeout, and only then the mac is fully shutdown. The problem from what we investigated and also talked with you, is that the Xsan process can't unmount the volume and stuck. We have also noticed that if we install a network extension and allow the popup of the network filters, i.e enabled the NEFilterDataProvider the computer is stuck, and the finder is in a non responsive state until a reboot (Also probably due to the fact the Xsan is now in a problematic state). This tests was done on latest versions of MacOs 13 & 14. We have taken a sysdiagnose from the computer while we have tested. Do you familiar with the problem (We got no answer on the feedback assistant)? Thank you, Idan

We have developed a DNS filter based on NEDNSProxyProvider. It works great for a minute, then it stops responding. Our logs indicate that during the outage our extension gets DNS requests and formulates DNS responses that it hands back to the OS, but from outside of our code it is as though our extension is not responding.

When installing a new version the app while a tunnel is connected, seemingly the old packet tunnel process gets stopped but the new one does not come back up. Reportedly, a path monitor is reporting that the device has no connectivity. Is this the expected behavior? When installing an update from TestFlight or the App store, the packet tunnel instance from the old tunnel is stopped, but, due to the profile being on-demand and incldueAllNetworks, the path monitoring believes the device has no connectivity - so the new app is never downloaded. Is this the expected behavior? During development, the old packet tunnel gets stopped, the new app is installed, but the new packet tunnel is never started. To start it, the user has to toggle the VPN twice from the Settings app. The tunnel could be started from the VPN app too, if we chose to not take the path monitor into account, but then the user still needs to attempt to start the tunnel twice - it only works on the second try. As far as we can tell, the first time around, the packet tunnel never gets started, the app receives an update about NEVPNStatus being set to disconnecting yet NEVPNConnection does not throw. The behavior I was naively expecting was that the packet tunnel process would be stopped only when the new app is fully downloaded and when the update is installed, Are we doing something horribly wrong here?

Hi, I have a VPN product for macOS. When activated, it creates a virtual interface that capture all outgoing traffic for the VPN. the VPN encrypt it, and send it to the tunnel gateway. The gateway then decapsulates the packet and forwards it to the original destination. To achieve this, The vpn modifies the routing table with the following commands: # after packets were encoded with the vpn protocol, re-send them through # the physical interface /sbin/route add -host <tunnel_gateway_address_in_physical_subnet> <default_gateway> -ifp en0 > /dev/null 2>&1 # remove the default rule for en0 and replace it with scoped rule /sbin/route delete default <default_gateway> -ifp en0 > /dev/null 2>&1 /sbin/route add default <default_gateway> -ifscope en0 > /dev/null 2>&1 # create new rule for the virtual interface that will catch all packets # for the vpn /sbin/route add default <tunnel_gateway_address_in_tunnel_subnet> -ifp utunX > /dev/null 2>&1 This works in most cases. However, there are scenarios where the VPN process may crash, stop responding, or another VPN product may alter the routing table. When that happens, packets may no longer go out through the correct interface. Question: Is there a way to reliably reconstruct the routing table from scratch in such scenarios? Ideally, I would like to rebuild the baseline rules for the physical interface (e.g., en0) and then reapply the VPN-specific rules on top. Are there APIs, system utilities, or best practices in macOS for restoring the original routing configuration before reapplying custom VPN routes? Thanks

I'm writing an LDAP Browser app using SwiftUI. I tested my LDAP code using a command line app that uses the exact same libraries and it successfully connects to my LDAP server over a TLS connection. I did need to install the CA cert into the system keychain. The SwiftUI version, using the exact same code and parameters returns an "Unknown CA" error. It works fine without TLS. Can anyone explain why certificate validation is different for a GUI app?