I had the same problems with 5/3/1. After a certain point, lifts respond differently to varying stimuli. Frequency is the name of the game for me with squat, press, and chinups. Bench I can hit heavy once a week with a 2 board or a bench variation focusing on tricep strength once a week as well. My deadlifts respond best to volume. Unsurprisingly, my only lift that went up on 5/3/1 was my deadlift. Squat and press felt cold and alien to me despite having been doing them for years, and bench press was stalled.