Hey man,
Try loading the Biskeydump payload, if you get a display here and if it has artifacting, then it’s likely a ram/SoC issue or a joint issue between them and the board.
You can then try putting downward pressure on the Ram ICs and see if that resolves the artifacts for confirmation, though sometimes this doesn’t work.
Failing that, I’d check your 8316 IC for you positive and negative 5V rails