I've been following this issue for some time and reverting to x11 in meetings where I am expected to share screen. This is a major annoyance, because Wayland is soo much more smooth (and uses less laptop battery too, for some reason).
Apparently what happened is that zoom would work normally under Wayland when it was started with xwayland up to right before v6 was released. Now they decided to disable the xwayland option and the window is now only drawn natively. The environment variable will not activate xwayland composition, nor changing zoom.conf.
I wonder if anyone managed to trick Zoom v6 to run under xwayland?