What’s the default login/display manager?
GDM. Gnome Display Manager. If you change it, it might break.
OK, changed it to sddm and it’s working fine, no issues.
And kde is working and selectable from SSDM. At least x11 anyhow, throws up some error when trying to login to KDE with Wayland
Yeah. I tried TDM, and it crashed when I tried to login to any de.
Did you disable gdm?