Dunno if this is a known bug but thought id mention it. Somehow the game corrupted my save data and there is no way to delete that save data in game. It instead makes most menu buttons not work, and if you try to play a song in practice, it boots the song but doesnt work. Unsure how my save data got corrupted in the first place but its probably worth finding a way to delete/restore corrupt save data so the game doesnt suddenly become unplayable.
btw issue is fixed once you delete all save data from the file