You are running into this issue:
There were some changes to how gnome-shell 3.38 launches Xwayland that broke X11 access to snaps. The same issue affects Ubuntu 20.10’s Wayland session.
We’ve got a fix merged upstream to revert the problem change that will be available in a 3.38.x maintenance release, which will probably make its way to Fedora 33 at some point. We’ve also been working on a change to snapd that would let X11 apps run without that fix (since the revert was not been merged to the master branch).