Yesterday I mentioned I was having audio issues with my Pixel. I never got it sorted out on the default Camera app, despite all the suggestions I found on reddit.
So I tried plan B: downloaded Open Camera from the Play Store, tried a few recordings on a few different instruments.
No audio issues. Good/decent sound quality.
I guess that's that. I ordered a USB-C microphone, too. Interested to try that when it arrives, see if that provides slightly better sound.