Since you transferred the rest from your old bow, I will assume that it is not the Lock Down model. A couple of things you should check are timing and how the rest is attached to the bow.

The prongs can be in the upright position but they need the final tension taken up on the cord to make them drop correctly. That should be the last 1-2 inches of draw.

The rest should also have at least 1/8" of space between the shelf and the prongs in the lowered position. It would be better if you had 1/4". That will help eliminate the bounce back that may occur with the non lock down models.

If you are still having problems you can do one of two things. I have the pdf that shows how to adjust the spring tension on the NON lock down models. I can send it to you and you can try it yourself or you can call QAD and talk to Patrick. He is very helpful and they will adjust the spring tension to fit your bow.

Unless you have a short draw of <29" and/or are shooting over 280 fps, you shouldn't have to adjust the spring. It is probably more of a setup problem. I just installed the new lock down model on my bow. I have a 28" draw and my arrows are shooting at 280fps. I didn't have to adjust a thing and it works great. I did, however, have to fiddle with the rest I bought last yeat but once I adjusted it, it worked great also. I sent it back to QAD because I had pulled the threads out of the body when tightening the screw and they upgraded it to the lock down model free of charge. Thats great customer service!