we are using C based Audio Graph API in our app, graph consists of MultiChannelMixer and RemoteIO audio unit, where we are using both input and output. We have also enabled background audio mode (using UIBackgroundModes in plist).
Now when we start that audio graph, everythings works fine. However, when we stopped that graph, the Microphone indicator appear for second or so, even when I am in foreground (on "square" phones - like iPhone 8 it appears for fraction of second, so that it is even more weird). See attached video, when I tap on camera button, it just calls AUGraphStop on running graph.
When I remove audio from UIBackgroundModes, the problem disappear.