This is uncommon but the easiest way to deal with this is to take a page from “5’s PRO” and start using “8’s PRO” or “10’s PRO”. Keep it mind that I’ve done all of these and if you are FT fibre…the 10’s PRO sucks.
So for example:
5x10 @ 70
These are %'s, by the way.
The key of the 5/3/1 program is NOT the sets/reps or whatever - it’s the 5 main principles. I’d also start supersetting the main movement with an assistance exercise. With squat/deadlifts - do dips. With bench press and press - do DB squats or DB SLDL (or something similar). This doesn’t have anything to do with your situation as it applies to most programs I write now.
So set your TM so that you can easily hit 10 reps on your last sets of your first cycle - in other words, work backwards. Then progress as usual. If you do this right and eat food - you can put on some serious size.
Let me know if this makes sense.