Please film so we can see your whole body - and a little in front of the bar so we can see stance/grip etc. But from this angle I can still tell you are not locking out at the top. Stand all the way up. Knees and hips in full extension. You are also rushing the squeeze part. Set your shins. Get your breath. Squeeze your chest up/back flat. Then pull. You are doing it all at once which will produce inconsistencies from rep to rep. Rep #5 was the best in this regard