Well I am also a newbie.
On your 87.5 Kg video pause at around 15 seconds. Why are you starting the movement by bending forward from the waist? Then, later your knees start to bend.
I think the movement should start by a slight unlocking of the knees and your hips should come down as if to sit simultaneously.
Also pause at 37 seconds near the ending. You are putting the weight back on the rack while bending forward unbalanced on one foot.