I think this bug could be related to Debian's bug: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=975453 They already got a fix.
** Bug watch added: Debian Bug tracker #975453 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=975453 -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to mutter in Ubuntu. https://bugs.launchpad.net/bugs/1905637 Title: Games don't go full screen correctly with newer version of libmutter To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1905637/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs