Since the problem doesn't seem to occur on any other systems except Fedora 33 X11/Wayland it suggests there is a problem in that system. IIUC Fedora uses XWayland which is an X11 frontend for Wayland rather than Xorg X11 itself, so probably there are bugs in that.
Basically doesn't seem to be anything Geany can do to help except say "use wayland directly" which seems the only workaround.