Our UE4 game is stuned when received notification from other apps. It will take 50ms-500ms to call [AVAudioSession sharedInstance]. This cause the main game loop can not to call FAppEntry::Tick() before the func returns.
[AVAudioSession sharedInstance] cost long time to return in UE4 app
AVAudioSession* Session = [AVAudioSession sharedInstance]; bool re = Session.otherAudioPlaying; //real cost is get otherAudioPlaying return re;