Hello,
IMHO, the start of the movement needs some tweaking. What you seem to be doing is moving your head/ shoulders back, while leaving the bar where it is. You are actually increasing the leverage, thus putting you in a disadvantageous position.
If you want to use the hip rebound, the bar needs to move back with the shoulders; then, as you rebound, it moves forward and leaves the shoulders, going up.
Hope this helps,
IPB