The issue was requested through the Apple Feedback app.

It happens on all iOS 16 devices. It happens easily if you play and stop it repeatedly. When playing, it seems that the error does not occur if AVSpeechSynthesizer is finely separated by spaces and played back. Errors do occur, but they may occur less frequently. I tested it with an app that plays TTS in that way, but the app didn't die. There are several symptoms when an error occurs. It can't stop playback, loses control, and continues to play until the end of a sentence. If an alarm or call comes in while TTS is playing, the phenomenon of listening through the earphones and playing back through the speaker also occurs. I temporarily took measures to prevent the above problem from happening without the app dying. A quick iOS update should fix this problem.

I am currently having similar symptoms. When I repeatedly play and pause using AVSpeechSynthesizer, I get that error right away. If you look at the forum posts, it seems that this error has occurred since the iOS 16 beta. However, it seems that Apple hasn't fixed this error yet. I have the same error on iOS 16.2 beta devices. I'm waiting for Apple to fix this issue when it finds out, because symptoms can easily come out by making a sample code and testing it a little. Or, wait for the news that Apple is preparing to release iOS 16.1.1.

In addition, this phenomenon does not occur or the afterimage seems to disappear quickly when the content is displayed on the dynamic island by running the timer of the alarm app or playing music in the music app. If the content is not displayed on the dynamic island by ending the timer or stopping the music again, the phenomenon will be reproduced again.

I have attached a link to a video of the phenomenon. Please check the video too. https://youtube.com/shorts/Lb4-yhTnMNg?feature=share

https://developer.apple.com/forums/thread/718088 Added more content. Please check

This is the cause of this problem I have identified. First of all, this problem occurs with apps that use the admob library. Among the apps I sell, there is a paid app with a different target (same code) in the same project. When I build this paid app in my project, I don't see this warning. My paid app uses "Other Swifts Flag" to not include the admob library in the code from the build generation, and the admob library is not included in the app. I contacted Admob and got a reply. Admob is also aware of this issue. Admob believes it's a bug by Apple, and Apple is also aware of this bug. Maybe it will be improved in the next Xcode or iOS update. My guess is that when using WKWebView in Admob, you get such a warning message.

First of all, this problem occurs with apps that use the admob library. Among the apps I sell, there is a paid app with a different target (same code) in the same project. When I build this paid app in my project, I don't see this warning. My paid app uses "Other Swifts Flag" to not include the admob library in the code from the build generation, and the admob library is not included in the app. I contacted Admob and got a reply. Admob is also aware of this issue. Admob believes it's a bug by Apple, and Apple is also aware of this bug. Maybe it will be improved in the next Xcode or iOS update. My guess is that when using WKWebView in Admob, you get such a warning message.

When repurchasing or restoring, the in-app product ID is the same.

Sometimes the app appears in the list again after completely closing the app in the background state.

Devices with older round home buttons seem to be less prone to the above symptoms. And it seems that the above symptoms occur more often on devices that do not have a circular home button. (This usually happens on notch devices)

We asked Apple for improvement by sending the code that reproduced the symptom as feedback, but unfortunately Apple was unable to reproduce or improve it in the end. We found a way to get rid of the symptoms and were able to make improvements before the official release of iOS 15. We found that MPVolumeView was the cause. If you use MPVolumeView in your app, try changing the location of the MPVolumeView declaration or its location.