OK, so that pretty much fault isolates it down to the specific application software (Zoom) that is trying to access the webcam.
Like(?) @FranklyFlawless, I don’t have Zoom installed and will always be trying to avoid installing it, so I can’t help you with Zoom.
You could look to see whether Zoom allows you to configure which webcam device it is using and, if so, whether the (one and only) webcam device shows up as an option to choose? Whether Zoom offers you some kind of test mode where you can at least see what it is seeing? Whether it actually gives you the possibility of placing a test call? And whether you get an error message at any stage?