You're doing a good job keeping your hips back on the way up, but you aren't descending that same way. When you hit the bottom there looks like there is slack in your hamstrings since you didn't descend with your ass back, so your bounce is working against you more than for you. As your hamstrings tighten to stand up your ass is rising faster than your shoulders and the bar looks like its moving forward towards your toes more. I think pushing your ass back on the way down will help keep you tighter and fix some of this. You can put a box behind you to reach for, or just think of pushing your ass back more and down between your heels less.