Look at Rep#2. See how on your knees and forward your are? This is prevalent in all of your squats. Two things are causing it. The biggest is knee cave. Get a shot from the rear, you'll see a lot of knee cave going on. You also don't get enough hip flexion (which makes the back angle slightly too vertical) going at the start. While shoving your knees out get your dick behind your heels a little more than you think you ought to. You're close dude.