Bug Unity Recorder hiding audio when recording a movie 2021.1.14f

oddd....

when I try to record movie with audio, it records the video, but turns off the audio.
When I stop recording/gameplay, i hear a half-second of the song that was in process, then the game stops.

If I un-check "Include audio", the game will play with audio, but Unity Recorder still records mute (as expected with include audio unchecked)

The game stopping is expected. But why does it mute the audio?

EDIT: It killed all audio in the game. I had to restart Unity to get audio back.

EDIT II: I tried adding an audio recorder, thinking maybe it needed to record the audio and visual separately, and then combine them, but no dice. However, the audio clip(WAV) did record the audio, (but not the video/MP4) even though during the recording, no audio was played.

EDIT III: now I can get no sound while playing, but it is recording the sound. AFAIK all my preference and project settings are back to default... but perhaps I changed something. In particular, I don't remember whether "enable output suspension (editor only)" in Preferences > Audio was checked or not. Not updated in the Unity Manual, but it is off.