Okay, so now looking back at this bug, I see that when I have Focal with X11 and the 440 nvidia drivers enabled, I can set scaling to integer multiples without problems, but enabling fractional scaling and then using a fractional scaling results in the black screen problem mentioned in this bug as well as this in the system journal:
gnome-control-c[6913]: Config not applicable: GDBus.Error:org.freedesktop.DBus.Error.InvalidArgs: Logical monitors overlap ** Summary changed: - [nvidia] all monitor scaling fails due to overlapping monitors + [nvidia] fractional monitor scaling fails due to overlapping monitors -- 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/1869042 Title: [nvidia] fractional monitor scaling fails due to overlapping monitors To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1869042/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs