In the CLI, xrandr --output MONITOR_NAME --brightness 0.7 seemingly "works" because no feedback is shown.
After using xrandr --verbose | grep Brightness, Brightness: 0.70 is shown as output but no visual changes occured.
I rebooted the system to check if this was needed but no.
An other xrandr --verbose | grep Brightness later, Brightness: 0.0 is shown.
Could this be related to my monitor being 'WAYLAND0'? If so, is there a way to change that? I run a Linux Mate 20 on the side, and my very same monitor is displayed as 'VGA-1' there, and xrandr works fine.
Thank you!
Edit: I went to /etc/gdm3/custom.conf and removed the # from #WaylandEnable=false, which gave me back the 'VGA-1' output after a reboot.
