I've same problem with nvidia 960 in combo with intel integrated card.
Even when I disable integrated card in BIOS, it doesn't help, but contrary making it default helps, but of course then system is using integrated card as main card.
I tried setting NOMODESET and WaylandEnable=false, but those didn't help.
Removing nvidia drivers and using noveau works.
I've same problem with nvidia 960 in combo with intel integrated card.
Even when I disable integrated card in BIOS, it doesn't help, but contrary making it default helps, but of course then system is using integrated card as main card.
I tried setting NOMODESET and WaylandEnable= false, but those didn't help.
Removing nvidia drivers and using noveau works.
Will also try replacing gdm with lightdm as suggested in https:/ /bugs.launchpad .net/ubuntu/ +source/ nvidia- graphics- drivers- 384/+bug/ 1705369