Comment 1 for bug 1487111

In the case of the microphone trust prompt, it could be explained by the fact that Pulseaudio times out and returns from pa_simple_new() after 30 seconds. Then the video recording starts with no access to the microphone while the prompt is still shown.

In the logs of the camera app we can see:
Failed to open a PulseAudio channel to read the microphone: Timeout
Failed to setup PulseAudio microphone recording stream