Is it possible to have different scales for join displays? I tried the solution suggested here: gsettings set org.gnome.mutter experimental-features "['x11-randr-fractional-scaling']" but it didn't do anything.
I have a laptop (with Debian 11 and Gnome 3 X11) with a 4K display and I got a second (portable) 1080p monitor.
For the main display, in Settings->Displays, I put a Scale of 200%. When I connect the second monitor, it works fine, but also has the 200% Scale, which makes it unusable.
I have the option to change the scale of the second monitor back to 100%, but then that automatically puts the scale of the primary display to 100% as well.
