I like how you ride, and you have a nice position. You have a good release for the height of the jump, you have a nice leg going over the jumps too.
A couple things I noticed is you jump ahead a little bit...your crotch is over the front of the saddle instead of the middle. Also on the flat, your lower leg is not that secure, it moves back and forth at the canter.
Maybe you can try shortening your stirrups a hole. I have the same problem with my legs sliding all over the place, when I shorten my stirrups it makes my legs feel more secure.