Wayland is still in development, despite it becoming the new default display manager since Zorin OS 17.
It is common that on Wayland, Zoom window will either not be properly rendered or will appear off screen.
Can you try logging in from your login screen on Xorg and then testing Zoom?
From your login window, clicking the gear icon will offer your options on which display manager to use. If you see Zorin Desktop and Zorin on Wayland, than the first is the Xorg choice.
If you see Zorin Desktop and Zorin on Xorg, then the second choice is Xorg.
If you do not see the gear icon, try selecting to log in as another user - that should bring up the icon - after selecting your desktop choice, you can log in as your normal user account.