I have the same problem using Davinci Resolve in fullscreen mode, as well as VLC. With two 27" 4K monitors it's impossible to use any other scaling factor except 150%.
Ubuntu 20.10 GNOME 3.38.1 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1871849 Title: Full screen videos suddenly change scale when using fractional scaling To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1871849/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs