Remeber the old xbox 360 glitch that allowed you to play 3 or 4 spilt screen zombies using a bug with deadops arcade? i just found it it works the same on ps4 and ps5! it works beacuse the ps4 and ps5 use signed in accounts instead of guest accounts like the ps3 version. it uses the sign in users simillar to the xbox 360 version
Do note that its extermely hard to make the bug work with 4 players. not impossible tho since some people were able to do it in the xbox 360 so it might work with the ps4 and ps5 version. xbox360 video