Comment 2 for bug 1886729

You certainly seem to have the latest and greatest Intel GPU which should support 4K up to 120Hz:

  https://ark.intel.com/content/www/us/en/ark/products/196597/intel-core-i7-1065g7-processor-8m-cache-up-to-3-90-ghz.html

So I suspect using "adapters" is the main issue. If you can then please try to get a Thunderbolt-to-DisplayPort CABLE. The Thunderbolt end looks like USB-C but it's much more capable and can carry a full-speed DisplayPort signal.

This is probably not a software bug, or if it is then probably not one we need to worry about if you just get a different cable. In the meantime you might want to try selecting 'Ubuntu on Wayland' from the login screen to see if the experience is any different there.