Rep one: You push straight up out of the bottom, you struggle.
Rep two: You press more diagonally, like you should, you don't struggle. Elbows are in line with the bar. Look how easy this rep is compared to the others. It's very smooth, very good. If you could get all reps like this...
Rep three: You touch too low thus putting your elbow-to-bar-relationship in a weaker position.
Rep four: Did you bend your wrists here? The bar looks a bit too much behind you. Your left arm also lags behind here (I think you've mentioned this before.)
Rep five...there is no rep five in the video...
Conclusion: What you need is just more practice to get a better bar path by hitting the same spot on the chest and keeping your elbows in line with the bar.
You could try a cue like "elbows forward!" to get them straight. (But this depends on your mental image of your elbow position.)
Look in SS, the bench chapter, at the pictures of elbow positions, your current set up
seems correct. (Some more opinions on this would be nice, I'm not 100% sure.)