Probably an imbalance between your dominant/non-dominant foot, could be a lot of things. Someone pointed out to me that I squatted with my right foot turned out a lot further than my left.
I progressed it like so:
3rd world bodyweight squat with both feet facing forward
Sitting in the bottom of the squat with enough weight to feel a stretch while keeping both feet in similar angles
Loading the bar with only enough weight to maintain the angle
Without going too deep into the topic, I feel my issue, and possibly yours, is a glute/adductor issue. Turning my foot out more helped me screw my right foot better into the ground at the expense of the other side.
TLDR: Less weight on the bar. Address and fix the issue. Reload the bar. Repeat until elite?