Be more patient with the bar. You are you standing up fully. Keep the shoulders relaxed, and just stand up with the bar.
After you adjust to the speed/coordination of using the triple-extension thrust efficiently, you'll fire your shoulders upwards while simply turning the hands (always squeezing the bar) over.
Bumper plates and calibrated bars often make a loud "ping" noise when the extension is used correctly.
DO NOT stick your hips out to try and meet the bar/gain momentum. The bar meets you. Stand up.