There are known issues with running X11 snaps on GNOME 3.38’s Wayland session, which is what Fedora 33 defaults to:
This problem is being worked on both at the snapd level and upstream with GNOME, as the above thread details. Unfortunately those solutions are not yet available on Fedora.
I don’t have a Fedora 33 system readily available to check, but you might be able to switch to the legacy Xorg session from the login screen just before entering your password: look for a gear icon or similar that will show a list of available sessions. If the snap works in the Xorg session, then this is likely the root cause of the problem.