FX Bobcat II Regulator Problem (1 belleville washer in front of regulator)

I must have had a regulator and main valve failure simultaneously. My Bobcat II is out of warranty so I'm going to attempt repair. The gun has been shooting fine then overnight, my regulator gauge began showing the same air pressure as my air cylinder pressure and the main valve also started leaking air from the hex hole in front of the breech block. When I took the bottle adaptor off of the front of the breech block, I found a single belleville washer sitting loose, in front of the regulator. In all the Utube videos, I have never seen a belleville washer in Front of the regulator. When I tipped the gun, the washer fell straight out. It was positioned so the Cup side faced the rear of the gun. Upon close examination, I found a couple small shards of metal on the two main regulator O-rings, also the O-rings appear to be damaged. I will call AOA and get some new O-rings unless I can find them at Home Depot. The regulator appears to have some slight scoring. Ill just wait and see about that. What was the single Belleville washer doing in front of the regulator. My regulator has 4 sets of 2 properly aligned washers on the rear side of the regulator.