This is not a new problem, and it affects every gdm3-based distro that I have used. Long story short; if you want to use modeset=1 with nvidia to get rid of tearing (which would be every linux Optimus user on the planet), gdm3 doesn't work. No one seems to know why. Change your display manager to lightdm and enjoy life again. I have two Optimus laptops.
sudo dpkg-reconfigure lightdm -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to mesa in Ubuntu. https://bugs.launchpad.net/bugs/1752053 Title: nvidia-390 fails to boot graphical display To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mesa/+bug/1752053/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp