I bought a pc today and installed ubuntu mate 20.04. It boots fine but after a few seconds red dots are all over the screen it looks something like this https://askubuntu.com/questions/653546/there-are-red-lines-on-my-screen. When I try to open up another console, I have to wait for a few seconds again to see the console when I try to go back on the graphical tty red dots are gone but I can't do anything on it
Fresh install, updated.
CPU AMD Ryzen 3 3100
GPU RX 570
Edit: I also tried installing latest proprietary driver and downgrading the kernel to 5.4.0-54 as it was recommended but it didn't help either.