Please delete /etc/X11/xorg.conf and create /etc/X11/xorg.conf.d/10-nvidia-egpu.conf only containing
Section "OutputClass"
Identifier "nvidia-egpu"
MatchDriver "nvidia-drm"
Driver "nvidia"
Option "AllowExternalGpus" "True"
EndSection
then remove the ‘nomodeset’ kernel parameter and reboot.
Edit: changed the identifier name.