Alpine foil 4.5 with 2014 Ozone Edge 19M
You're choking the hell out of that kite. You need to let it breathe much more.
When you have the kite at 12, pull in a little to get enough tension in the back lines to get the kite to turn. As the kite dives, push the bar out, the kite will fly a LOT faster and as you turn it back up you can start to pull in a bit, but nearly never the whole way. You need to get that kite flying fast so that when you DO pull the bar in your have all that power built up from the dive of the kite.
Also, the fact you're having to almost lock the bar to keep the kite tracking doesn't make any sense either. That kite does not look like it is trimmed well at all.
With the kite above you in 8 knots, you should be able to pull the bar the whole way in with little to no back stall.
Let the kite breathe and it will work a lot better for you
the problem is the wind was not 8 knots, it was more like 4-5 knots. The kite was back stalling it was running on apparent wind, as soon as the speed slows it dropped to the water. I had to depower all the way and do a few kite loops to get started, that is why you see all the twist on the line.