Repro drop targets are made of a different plastic composition. Originals were more rigid. Repro have more flex and absorb contact.

There's a few things you can try ;

As Daniel advises - Move the assembly a little more forward - this will improve the frequency of the target dropping.

What I do is really simple - Stretch the rubber behind the targets, or go to a lower size - so it stretches more and the target won't bounce off the rubber. My Paragon had this exact problem. I fixed it by stretching the rubber (which makes the rubber thinner) behind the targets and leaving the slack on the other side of the posts. There's a school of thought that rubbers produced today are slightly thicker than factory. I don't beleive this completely, but I have seen some rubbers that are definitely thicker.