The very first movement should be the hips driving forward, and then secondly the arms drive the bar up (utilizing the bounce created by the hips rebounding). You seem to be putting the hips second. And your hips are not rebounding fast enough.
Work on your timing. count it in your head: 1 - 2. 1 = hips. 2 = drive the bar. Start somewhat slow at first, so you can feel the bar dip down a little (the bounce) when you drive your hips forward. Hips, feel the bounce, drive the bar. As you get the timing down, speed it up. This may take a couple sets, it may take practicing over a few workouts.