Your heels could be pushed down more and your leg looks a smidge too forward, which may also be playing a role in your jumping position. Push more into your heels (without standing and no knee gripping, think of your calf as being the point of contact and your knees as shock absorbers) and think of bringing your belly button down to the pommel of the saddle and arching your back like a cat (although not too exaggeratedly). You're too upright, so think of bringing your forearms down more into your horses neck.
I know you said you w/t/c in two point just fine, but have you tried it with no reins? Go back to basics, get on a lunge line and take the reins away. If you're truly in the correct position, you should be balances, butt not touching the saddle, not posting (if trotting) and not leaning on the horses neck. A lot of people think they're two point on the flat is great, but it falls apart when the reins are gone since they are balancing on the horses mouth. I feel like this may be your problem.
Also try going over some poles or small gymnastics in your two point, both with and without reins. So assume the position on the flat and try to hold if over the poles. It should get you started with thinking about how you're doing it over the jumps.