OK, you have gripped too much with your knee. When you do this, it takes the lower leg off your horse's sides. This allows it to slip back. When the lower leg falls back, it loses its ability to counterbalance your upper body. As a result, the upper body topples forward and has to be supported by the "crest" release.
You need to lessen the grip with your knee and hold the horse with the inside of your upper calf/lower leg. Then, you need to relax your knee and allow your seat to come back and hover over the middle of your saddle. Here, you are way over the pommel of the saddle....too far forward.
I have my students doing two point with no hands on the horse's neck. That way they learn to keep their lower leg forward, to balance the weight of the upper body going forward. The farther forward the upper body goes, the MORE forward the lower leg. Keep that lower leg at the girth.
The lower leg slipping back is the most common mistake riders make, and we ALL do it, especially over the bigger jumps.
In this photo, my lower leg has slipped back a bit. However, see how my seat has gone back to help balance the upper body? I could certainly have a bit more weight in my heels, too.
My big question when I go over a jump....if I were standing on the ground, in the same position I had when going over the jump, would I be able to maintain my position? Or, would I fall forward on my face? When jumping, you have to always be able to envision "landing on your feet".
Does that make sense to you? Look at the two photos and see if either of us would be "balanced" if out feet were on the ground.