Ubuntu 22.04.2 and nvidia drivers behave badly

Fresh install of 22.04.2 on a Dell with a GTX1070 nvidia card.

  • Nouveau driver: no issue
  • Nvidia driver 530 (cuda), 525 (cuda), 470 (just graphics): only one user can log into gdm. Any second user will be returned straight to the login page.

I did not see any obvious contents in the logs pointing to a root cause.

FWIW, I replaced gdm3 with lightdm, and … now it works.

nvidia-smi confirms that 2 Xorg session are using memory in the Graphics adapter.