I don't think it's bouncing back up. I had a similar problem with the HD that is on my 3d bow. What I found was that there was too much slack in the restcable and it was not bringing the rest back all the way every time. When it did not bring the rest all the way back the rest wouldn't drop until the vane hit it. I tore some vanes off of a couple of arrows until I figured this out. I shortened therest cableabout 1/8" and now it's working perfectly.

Try that and you should see an improvement. Good luck.