I have the same problem. Opening Photobooth after starting the meeting worked for me (then continues to work if I quit Photo Booth ... until the next meeting : / )
I've still got an open support ticket, and have been pinging Zoom weekly. The current status is that they are (still) waiting to get a response from their engineering team who is supposedly working on this issue.
I opened a ticket with Zoom support a few weeks back and I just had a call with their engineers to show them the issue and sent them a logs of what's happening on my computer, so hopefully, they will be able to fix it soon.
Same issue as everyone else here: monterey, mcbook pro 14 m1 pro, low quality on 922pro, until I launch facetime and then I am in HD for the rest of the meeting. Unbelievable.
I've had the same issues since I got my new MacBook Pro that only has USB-C. I have USB hub and it works great everywhere else but for some reason Zoom doesn't default it to HD. The HD checkbox is also disabled in my client (though in the web interface I've enabled HD video). I'm on Big Sur right on a 2019 MBP. The LogiTune seems to get Zoom to recognize the proper format but without it, the cam is stuck in a 4:3 setting (only in Zoom).
I think Zoom has given up on this problem. I got this reply today from the ticket I had open.
I have bad news. So after investigation of this issue. We have found that the issue is that there is something wrong with the 720P of these Logitech cameras on Mac OS Monterey. We can’t fix the issue on zoom’s side. And we may advise you to ask for the support of Logitech or use full HD (1080p) or continue to simultaneously open Logitune while using Zoom as a work-around solution. I am sorry to have to give you this bad news. We did a lot of work on this and to find that we can't fix it is very disappointing on all sides.
What I wonder about this message is: why is literally EVERY OTHER APP on macOS doing fine and can use the 1080p stream of the camera, displaying a tack sharp image? Obviously every other software developer is doing something different than Zoom if it works fine there.
It sounds to me like Zoom is, even in HD mode, never requesting the 1080p stream but only the 720p stream. And once you open another app that requests 1080p, the webcam switches over and Zoom can handle it fine. So my question: why can't zoom just give me the option to request a 1080p stream (or automatically do this when HD is selected), as clearly every other app can do this already?
I'm so glad I bought this camera SPECIFICALLY to use in Zoom meetings that i'm in all day. I absolutely love entering the room looking like a blurry potato until I open another, better app, which finally triggers my camera to work properly. I especially love having to repeat this process every time i move among the breakout rooms.
And just like Homer, the magical man from Happyland in a gumdrop house on Lollipop Lane..... I'm being sarcastic!
For those having this issue, LogiTune seems to be the best application I've found to help here. You still have to open it for Zoom to detect the proper format coming from the camera but I've got the clearest picture using LogiTune versus others.