USB camera is really slow to start up in Google Meet on Chromium browsers on my M1 Macbook Air

Things were working great on my M1 Macbook Air until recently, when suddenly my USB camera (a Panasonic digital camera connected via HDMI - USB capture card) started acting weird, and now it takes forever (maybe a few minutes) to start in Google Meet on chromium browsers, e.g., Chrome, Brave, etc. Just Google Meet. Just on Chrome and Brave.

When I start a Google Meet meeting, the audio starts up ok, but the camera image is black for a few seconds, and then it captures a single frame which remains frozen on the screen. After a few minutes - maybe 2 or 3 - the camera eventually starts working. This weirdness happens each time I start a Meet, even if it's just a few seconds between ending one and starting another Meet.

When I go to the Video tab in Google Meet settings, while the camera is frozen it says "Camera is starting". My built-in webcam works fine, as does a USB Logitech webcam.

I know the natural conclusion would be that there's something wrong with the camera, but this issue only happens in Chrome and Brave. I don't experience this problem anywhere else as far as I can tell. Google Meet in Firefox, Opera, Safari works as expected – the video starts up immediately as soon as I start a Meet. Zoom and Photo Booth work fine as well so it's not like the camera isn't talking to the computer.

When I watch the Activity Monitor while this strange behavior is happening, there's a process called VTDecoderXPCService which shoots up in CPU use over the course of those few minutes. Once the camera starts working correctly, it immediately drops back down to a reasonable level. The User is listed as _cmiodalassistants (262). I have to conclude that it's directly related to the problem. Force quitting the process doesn't fix the issue either.

I uninstalled Chrome and followed the instructions on chromeisbad.com to remove all traces, and then reinstalled. No dice.

The one change I made to my system recently was to install CleanMyMac, which I soon uninstalled after realizing it wasn't helpful. That might have been a mistake, but it's weird to think it would cause this issue. The only thing I can find on the internet that might be connected to this issue is that some people on Final Cut Pro forums say that CleanMyMac can completely corrupt your system and a wipe and reset on MacOS is necessary. I'd really rather not do that unless it's necessary.

Any help or insight would be incredibly appreciated!