Involuntary microphone level resets with Zoom lately

Lately I've been experiencing spontaneous microphone volume level resets to a low level, notably when using Zoom. Sometimes when it happens, I tried resetting alsa:

pulseaudio -k && sudo alsa force-reload

But this oftentimes disconnected the microphone altogether or had no helpful effect at all. I also tried disconnecting and reconnecting the USB cable to no avail.

As I depend on video calls a lot, I have for the first time come close to fantasies about getting a Windows machine just for that, just to say how bad it is. I wonder if this is anything in recent 20.04 software updates, or how would you approach this. I tried switching between two Logitech webcams only to have it reproduce a lot in both. As much as I recall, this type of problem never happened before for me (using these webcams).

In recent days I have noticed that the volume level of the mic resets in the Ubuntu settings application, and then I'm able to pull the mic volume up again to regain normal usage. But then it randomly happens again a few minutes later all over.

I think I also encountered the same problem yesterday. Have you checked the zoom settings for Audio?

Go to "settings > Audio" and untick the "Automatically adjust microphone volume".

This helped me yesterday. Hope this helps you too.