The gear for choosing X11 / Wayland on login screen is absent. X11 starts silently.
Made a new user and the gear was present for the new user (only for him). After reboot again silently starts X11 and no option to choose. For old and new user.
~$ grep -i WaylandEnable /etc/gdm3/custom.conf
WaylandEnable=true
What's wrong with this system?