Since changing to Ubuntu 22.04, the system does not detect external screens anymore

With windows everything was working fine (external monitor (dell) connected by an hdmi-dvi adaptercable)
I installed Ubuntu Jammy on my Asus Rog zephyrus. At the beginning it recognized my external screen, but it was not possible to “connect” with it properly. When chosing the screen in display settings, it stayed black. Then i installed newer nvidia driver, 525 made my system crash so i sticked to 510. but it didnt recognize the external monitor. downgrading to 470 didn’t help either.
other things i tried:

  1. update Nvidia Drivers/ubuntu updates
  2. different gnome display manager checked:
    - wayland & xorg/x11
  3. toggling secure boot
  4. check for missing kernel headers
    - sudo apt install linux-headers-$(uname -r)
  5. nvidia-smi no errors, shows the 510 driver
  6. tried with a displayport, which didnt work as well
    anything else i can do?

maybe install drivers for displayports or anything? I’m out of ideas…

thank you in advance.


when the site lets me upload my then i will do. but it uploads for 15 min (400kb)
dont know what the problem is there