Firstly, that is some heavy weight. Nice job. A 3 RM is unlikely to be the prettiest set of squats you can do, so that is also important to keep in mind.
You are leaning over a little too much and probably flexing you back slightly. This results in you doing more of a good morining where you are forced to lift your chest midway up with the bar rolling around on your back. A rear oblique view would confirm this. Stay tighter and think "Chin down, chest up" as you descend and ascend. Relax nothing as you drive the hips strongly to the top. Keep thinking "hips" half way up through the ascent to help with the sticking point.