how heavy is the bar?
i ask because i find the bar is more inclined to swing back towards me off the floor (good) rather than swing out away from me (bad) when the bar weighs more than i do.
when the bar weighs more than i do it tries to pull me forwards. to counter that i need to transition my weight from the midfoot / ball of the foot at the start to the heel. some people say that actively contracting your lats will help it swing back but everett has this article on the first pull where he reckons that it simply will happen all by itself once the weight gets heavy enough.
one possibility is that there isn't room for the bar to swing back without taking your kneecaps off. if that is the case you need to frog your legs out to the sides more.
experiment with vids and see what seems to result in a good barpath.