A few things to check:
1)in the uncocked position, look from one cam to the other along the bow string. Where the bow string crosses the rail-stock, does it hump up as it crosses?
2)with the string dampening system removed and the crossbow in the uncocked position, mark the stirrup side of the rail-stock from the bowstring toward the stirrup about 3/4" with lube, white out or something similar. Now shoot an arrow. What one is looking for is how far the bowstring travels forward from the normal point of rest. The bowstring would have to ride the rail for this to show. If the string stop is set lightly touching the bow string in the uncocked position as one would like to have it, the bowstring coming down, hits the stops like hitting a brick wall.
I have modified the Ten Point String Dampening System with the adjustable rods on my Barnett Ghost 410's. I have had to back these off 1/4" or more as in no time the rubbers are split. Using the rubbers that Barnett sells, are worse as the rubber is softer. Setting close the bow string eventually drives the rubbers farther onto the holder or rod causing the rubbers to split.
3)does the rubber stops center properly on the bowstring?
All the best.