I think you should also make sure you set your backangle faster. You are done setting it when you are almost all the way down. But knees and back sould be set about the same time. Then when you are down there you come up with your butt way faster then your chest for a bit. This way you might squish your hips a bit every time. My guess would be (not a wild one) that you allow your hamstrings to get longer while you drive up for a short ammount of time which leads to the whole torso leaning forward a bit. Look at the position of your knees. They dont stay in place if we think about their position in a frontal plane.
Also: shove your knees out more than that. See how you cave in when you come up? That will reduce the space for your softtissue.
I hope this helps. But keep in mind I'm not a specialist on this topics.