I can think of two reasons why the draw hand drops.One is that you are deliberately pushing it down at the point of release( even if you are unaware you do ). The other is that the draw elbow is being dragged down during the follow through, and the draw hand follows it. The scooping up after is simply an attempt to correct a mistake.
The release is the part that is done without thinking about it. I feel that is the most important way to look at it.
When you have a release problem,the first thing you do is try to change it. Then what? You start thinking,yes?
So, how to change it without thinking??
I would try drawing the last part of the draw with the draw elbow staying level. If you normally draw the elbow down, then level will feel like uphill to you when you first change. Conentrating on the elbow will keep the mind off the release. After every shot you should be able to answer this question," Did you drop the elbow or did it stay level during the follow through?"
If the problem is brought on by pushing the drawing hand down without being aware, then it would be worth considering the contact bewteen index finger and under the jaw at full draw.That should feel solid, and should remain solid even after the arrow is on its way.Often,the contact is too light; sometimes the platform takes away the sense of finger against jaw. So, shoot with a solid contact, and feel that all the way to the end.( the hand will eventually separate,but don't make it separate. It will happen by itself.)
When trying to make changes to form, it is very easy to want to shoot normal rounds and keep scores. That leads to changes being put aside for the safety of the old routine. Form changes are better made when there is nothing to distract from those changes. No scores; no rounds, no need to score well.Making the changes are better done when the shooting format is as different as possible from routine. By that I mean shoot with a different goal in mind. Take away the sight and the gold. Shoot up the field to see where the arrows land. Use the point of the arrow on a clump of grass, or a flag stuck in the ground at 60y or so. The intention is not to hit the flag, but not to miss the archery ground!! Just shoot, and enjoy the freedom. If you are using a clicker, try to get through with no hesitation. If you shoot without a clicker try to get the arrow away without stopping the draw. Do not stop the draw just to get the arrow point dead on the flag. If the arrow point is close enough to the flag( or clump) shoot..... remember all you want is not to miss the archery ground. Doing things that way,is very different from routine and it is easier to work on changes.
Once you start to feel that you are succeeding with shooting arrows up the field, without stopping the draw for anything, you should start to see the arrows getting closer together in the grass. That should give you a positive sense that things are improving.
Next, start to watch the bow hand during the shot sequence. As you have become used to aiming( simply) with the arrow point, looking at the bow hand instead is only a small change. Aim with the knuckle that is easiest to pick out against the flag. The arrows will land a bit to one side of the other groups and possibly a bit further down range. That is to be expected; you have adjusted the "sight" heehee??
Once you are used to doing that, keep your eye on the bow hand for longer than normal. Watch it after the arrow is released. Try to see which way it moves. You are now trying to let the hand stay on target more or less. Not forcing it but "allowing it" to stay on target. It may twitch a little, but it shouldn't drop like a brick, nor should it flick over to the right( if you are right handed archer). When you succeed in watching the hand and find it is staying close to the target after release, you should also find that the hand's final position on any shot, will give you a clue about where the arrow will be.