Flatpak on linux is a different animal. First find the yellow exclamation button in plugins panel of preferences window, determine what the issue is from the error text (post here if you need help) and then you will likely have to gete shell inside flatpak container and do something there but it depends on the error.
The quick solution was to revert back to 9.0.4 (not 9.0.5 because broken routing) to be able to complete and send out designs to PCB house….
I will fault find when i got some time on my hand…
73/ Marcus