The problem most likely is that your graphics hardware is too new for linux. The firmware to drive it may not be available in Ubuntu yet.
You can do one of 2 things
- wait for Ubuntu to include the required firmware. It may appear in the next release.
- find another distro that has support for new hardware.
I had a similar problem recently and I used MX21.2.1"ahs" . The “ahs” stands for advanced hardware support. That MX version may include the firmware you need.
The other option is to use a rolling release distro like Arch or Void.
Regards
Neville