Nvidia-driver-440 (ubuntu version) boot to "hang" if prime-select nvidia on RTX 2060M (Tuxedo XP1610 laptop)

This Saturday I decded to upgrade my Ubuntu Budgie 18.04 to 20.04… Dumb, I know, it was working fine with kernel 5.3.0 and nvidia-driver-435 (from the graphics driver PPA).
The upgrade went fairly well, apart from this issue:).

The behaviour is thus:
If using the Nouveau/intel OSS drivers, the machine can boot to display manager (tried gdm3, lightdm and sddm with all scenarios, same behaviour).

If using nvidia-driver-440 and “prime-select intel” has been run (does not work with gdm3, since it prevents the VTs to be managed by getty… Nowhere to log in) it will likewise reach/display the login screen (and allow a log in).

If using nvidia-driver-440 with “prime-select nvidia” or “prime-select off-load”, it will boot to the kernel splash screen. AFAICT it actually starts X, i can see the display manager and Xorg as consumers in nvidia-smi, but it seems (from reading a lot of Xorg logs) that no modelines are generated whatsoever!?nvidia-bug-report.log (2.3 MB)

I’m sure it is something silly, like a leftover config file or something… But I just can’t find it.
TIA for any help!

Please delete /etc/X11/xorg.conf

Oh man, I was sure it’d be something really silly… But that…!
Talk about not seeing the woods for all the trees:-).

Thank you very much!