Single player, no problems.

When playing with 4 players split screen/4 quadrants, the left 2 flicker. Almost looks like the karts/characters switch quickly back and forth.

I've been searching for something similar and found something about an alternating frame being displayed every other frame. The discussion was about displaying 30FPS instead of 60FPS.

FYI, my system is not very high-powered but even the 4 player seems to be playing OK, just that this flickering is happening.

Any thoughts or ideas to address this? For now, I just don't play the 4-player.