I am attempting a Xinerama 1 with a GeForce 970GTX + Steam Proton. Now, I tried this with GDM3 and Xinerama 1 will result in a black screen. I am running the 390 drivers.
In an attempt to get this to work I switched to lightdm. It in fact does Xinerama the screens but it gets stuck after login. So I login... and it shows a zoomed in beavery thing background spread across three screens. However it fails to finish the login process to my normal desktop. So it gets stuck with no icons or menus and only access to TTY not ctrl + t terminal.
I feel like I'm so close. I've spent about 4 hours debugging this since I put in the new card. Any ideas?