Ubuntu 20.04 LTS (Same issue on 18.04 LTS)
Nvidia GeForce 970 GTX
Turning on Xinerama “1” crashes my GDM3 so that I have only black screens and a mouse cursor + TTY. In lightdm it will allow me to get to the login. I will be able to login but then it hangs and I am stuck without menus or icons and the ubuntu wallpaper (I also have TTY access).
I don’t know what the issue is. Also on a side note every time I boot my computer up I have to reconfigure X11/xorg.conf so that my screens are laid out in the right order. How do I make these changes permanent? Running XServ as root was the same issue.