you can run "sudo touch /var/lib/gdm/gsd-debug-randr" and restart gdm and you will get a debug log /var/lib/gdm/gsd-debug-randr.log with details on what g-s-d is doing
you can run "sudo touch /var/lib/ gdm/gsd- debug-randr" and restart gdm and you will get a debug log /var/lib/ gdm/gsd- debug-randr. log with details on what g-s-d is doing