"The Scheffler Bug"
The bug is related to the last round and having an actual AI playing partner. To replicate it (at least on the PS5), simply start a tournament and play through the first three rounds (I usually do this on the quick play setting where you only play a few holes a round). Obviously, make sure you use the setting that allows you to play with a computer player pairing in the final round. When you get to the 4th/last round of the tournament, save at any point and quit. When you come back in, regardless of who your initial pairing at the start of the 4th round (I've had Finau, Catlay, Spieth, etc.), it's switched to Scheffler and his scorecard is blank. The announcers dialogue is wrong when they speak about his score as well (probably matched to whomever the actual pairing was supposed to be with).
Furthermore, if you enter a playoff under these circumstances, at the end of the fourth round, it's typically blocked after you finish the first hole. Just sits on a landscape picture with nothing progressing, which in terms of criticality is just shy of a total game crash.
The issue really has something to do with the save and reload. Whenever I've played that last round without saving and coming back it seems to work fine. I have not tested this with playing full rounds through a tournament, but it is consistently happening with quick play rounds on the fourth round with an AI playing partner. I have also not tested to see if this happens with a playing partner during other rounds (not sure if that is a setting or not).