I have recently installed Ubuntu 20.04 on my laptop. When I connect to external screen and boost the ubuntu, the external screen can display, however the built-in screen remains in active black.
I still be able to drag the apps to the built-in one, thus I suspect it still functions but just not able to display. My laptop is ZenBook-UX431FN with Intel UHD Graphics 620 and GeForce MX 150 which builds on top of NVIDIA Optimus. I believe that's the cause of the trouble.
Can anyone help letting these two screens function? Thanks a lot.
Edit: Both monitors can be detected NVIDIA X Server as prime display, I can not adjust them.