I have 2 screens attached to my EndeavourOS (KDE Wayland) PC. The secondary is HDMI the primary is Display Port. The boot menu and boot messages all appear on the primary display, but once the login appears the password entry defaults to the secondary. How do I force it to default to the primary?
xrandr is Xorg only, it doesn't work with Wayland. You should be able to make SDDM use your Plasma display configuration - https://wiki.archlinux.org/title/SDDM#Match_Plasma_display_configuration
No clue if that's going to fix your issues, but at least it's supposed to work with Wayland.
Ok that explains it. I tried applying the plasma config earlier. Didn't fix.