Black Screen when strating display-manager after upgrade to Ubuntu 20.04. with nvidia drivers (Geforce GTX 950M)

Thanks to generix I was able to get the Performance Mode (NVIDIA-only) working.

The final step was to have no xorg.conf at all and let ubuntu prime-select handle all xorg configuration via files it autogenerates in /usr/share/X11/xorg.conf.d/
After deleting xorg.conf (and a lot of additional steps I’ve already done up to this point) - NVIDIA drivers are working fine now.

For comparison:

$ inxi -G
Device-1: Intel 4th Gen Core Processor Integrated Graphics driver: i915
v: kernel
Device-2: NVIDIA GM107M [GeForce GTX 950M] driver: nvidia v: 455.45.01
Display: server: X.Org 1.20.8 driver: modesetting
unloaded: fbdev,nouveau,nvidia,vesa resolution: 1920x1200~60Hz
OpenGL: renderer: GeForce GTX 950M/PCIe/SSE2 v: 4.6.0 NVIDIA 455.45.01

$ xrandr --listproviders
Providers: number : 2
Provider 0: id: 0x1b8 cap: 0x1, Source Output crtcs: 0 outputs: 0 associated providers: 1 name:NVIDIA-0
Provider 1: id: 0x1de cap: 0x6, Sink Output, Source Offload crtcs: 3 outputs: 3 associated providers: 1 name:modesetting

hope this helps others also stumbling at this point!

Cheers and happy winter solstice!