We have a Video Game running in Mint 19.3 (Kernel 5.4.0-70) on a B450 Mini-iTX Motherboard with 8GB DDR4 3200 memory, Ryzen 5 1600x CPU, 64GB Optane NVMe and one of several types of NVIDIA RTX 2080 graphics cards.
We run 4K @60Hz on multiple monitors; a Primary monitor is always present and connected via HDMI, but in some cabinet configurations, we have a second monitor connected via USB-C (DisplayPort) that displays an inverted view (think Battleship arrangement, back-to-back) where the player stations are on opposite borders of the display.
Up through Linux drivers 440.1 everything works perfectly. Past that, (currently 460.39) and needed for 30xx cards, the USB-C video output gets crazy. The image is duplicated on the monitor and squished to half-height, with a thick green bar across the middle. Note that in the pic below, we extended the desktop, as opposed to the arrangement we run in Production
To see the game “in action” with this problem, in our ENG lab, please see the YouTube video here:
Oddly enough, we only see this behavior when we ONLY have HDMI + USB-C. If we add a DisplayPort-connected tertiary monitor, the problem goes away!:
Due to posting limitations, I have to cut this post off, but I will try to add another right behind this one.