Ok, I found & fixed the issue : your player 2 control was assigned to Controller 2 with a button being #134 and another being #136. The game didn't expect a controller to have so many buttons and thus failed at processing their state correctly, leading the game to think they were always pressed down..!

There's still one mystery though : how was it possible to get these 2 buttons assigned ?

I noticed you already changed many settings in the game, did you also change the player 2 control settings as well ? Did you have a controller plugged in at this point ? Or maybe a 2nd keyboard ?