you're probably right but would be good to see a vid too.
with both back and front squats perhaps try some pauses at the very bottom for several seconds or so and do some work from full squat to parallel to get comfortable/strong down there/in that position. re OHS try it with a shoulder width/narrow grip and do likewise lots of short movements deep in the squat and pauses (light to medium weight 3-5 reps for multiple sets with very strict form)
basic good mornings ie knees slightly bent/just unlocked, feet shoulder width/receiving position stance are very useful IMO
another movement to try is deep squat holding a disc out in front at arms length just to activate/warm up key muscles etc, you won't handle much weight unless your shoulders are bigger than your head!