I'm having a similar issue with my apps which have an audio input feature. One of them uses 44100 as a sample rate and got the error on iOS / iPadOS 16. In that case, AVAudioSession.shared.sampleRate seems to be 48000, and changing the sample rate to 48000 resolved the error. Another one uses 11025 as a sample rate. This app needs to use a lower sample rate than 44100 / 48000, but I'm not sure how to workaround.

Still having this issue on iOS 15 beta2. I guess that an AdHoc *.ipa built with Xcode 12.4 is NG, but one built with Xcode 12.5 seems to be OK. Can anyone double-check?