I have (possibly) good news. SKTestSession.failTransactionsEnabled has been depreacted since iOS17, but it behaves strangely on iOS17. (lldb) po session.failTransactionsEnabled false (lldb) po session.failTransactionsEnabled = false 0 elements (lldb) po session.failTransactionsEnabled true We may work around this issue by not setting a value for this variable. // before session.failTransactionsEnabled = false // after if #unavailable(iOS 17.0) { session.failTransactionsEnabled = false } In iOS17 we probably need to use simulatedError(forAPI:).

It is fixed in iOS15 beta7 !!

Note: Stereo Audio Capture sample code. https://developer.apple.com/documentation/avfaudio/avaudiosession/capturing_stereo_audio_from_built-in_microphones This project always will not work unless the language setting of the device is set to English. For iPad, additional patches are required.

I also happened to this issue. iPhoneSE2 iOS15 beta6 Xcode12 and Xcode13 beta No error detected, just silence.