1 - It comes from the graphical displaying.
So it could be either hardware graphical related (aka GPU or display) or software graphical related.
2 - It doesn’t seem to come from driver or software issue since Windows didn’t work.
So it’s surely related to hardware, display or GPU. If it’s a desktop as other said you could try to change the output port of your display on your GPU…






If it’s just streaming (from big providers or home server) and that the device doesn’t not really do transcoding, try to find an used mini PC with decent specs (the only problem will be to find a PC that uses 4k@120hz but it’s really not a problem to have 60Hz cause most of the movies are going to be 24 or 30 fps…) And you’ve got it for 50$