The solution to this is to run X11 as root, so it can use VGA arbiter and detect displays on both the NVIDIA and modesetting drivers.
Add this to /etc/X11/Xwrapper.config : needs_root_rights = yes -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1716857 Title: gdm3, hybrid nvidia with modeset=1, no external monitors detected To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gdm3/+bug/1716857/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
