New issue with nvidia-prime and Nvidia Optimus



I am having an issue that I did not have before. It may have broken something in my setup.

I have an Nvidia optimus / dGPU and proprietary drivers. Now, everytime I switch with prime-select nvidia and logoff, I get a blank screen (no lightdm).

Same problem after a reboot.

I then have to boot in recovery mode in grub and switch back with prime-select intel to recover the LightDM logon screen.

Any suggestion? What kind of setting (LightDM, Grub) or missing package should I check?

Thank you!