How to disable wayland in 17.10 in gdm3 login screen

I just installed ubuntu 17.10. I'm using a Ryzen 1200 CPU and an RX-560 GPU with a 2580x1080 60Hz monitor.

The monitor is connected to the GPU through an HDMI cable.

When I'm using the native monitor resolution of 2580x1080, in the wayland session, the screen makes these very weird glitches. The glitches look like a refresh rate issue, one that is fixed by v-sync, but they are very intense and on the whole screen. As soon as I change the resolution to a lower one the screen becomes normal.

In the x.org session I can use whatever resolution I want, everything works great.

The problem is that during the boot-loading screen (the one that says "ubuntu") and at the login screen I see the same glitches on the screen until I login.

Is the boot-loading-indicator using wayland? Can I make it use x.org/x11? The same for the login screen?

You need to edit /etc/gdm3/custom.conf, change this line:

[daemon]
# Uncoment the line below to force the login screen to use Xorg
#WaylandEnable=false

to

[daemon]
# Uncoment the line below to force the login screen to use Xorg
WaylandEnable=false