One thing to keep in mind is that the squat is the most technical of the powerlifts. So for me, what that meant at one time is that I had to ‘practice’ the movement in order to get pounds on the bar. I think the 3x squat template could be good for that.
Also, it might be a muscle thing. It could be time to beef up your legs. Don’t be afraid of things like leg extensions, leg curls, and leg presses because you think they might be ‘non-functional’. Muscle is muscle and when you put a bar on your back that could potentially crush you often enough, you’re body will find a way to use that extra leg muscle. Split squat variations are great too. Of course, front squats are awsome because they can do this while also ingraining good squat habits.
I liked to do squat variations 3x a week while I’ll only do barbell bench and barbell deadlift variations once a week. I had a heavy day, a hypertrophy day, and a day where I’ll follow the lower to mid range of prilepin’s table in 70-85% range and try to move the bar as fast as I can. I just put that there for an example of how to set it up without killing yourself.
I remember in one full body template by Wendler, you do just the minumum reps twice a week and once a week push it. I also think I remember that as you acclimate, you can start to add reps to the minumum. I’m already thinking of zillions of ways you could set this up using 5/3/1 ideas and principles to creat your own template with it still being 5/3/1.