Valve wont fill past 3000psi?

Morning, all

Originally, I had thought perhaps that my CF tank was leaking. I would fill it up with the compressor and then some days later, use it to fill a gun and it would only fill to right at 3kpsi.
Today, I topped it off and it was near 4kpsi. Filled to just under 4500 and went to fill a gun. Simply will not go past 3k psi. Not on the tank gauge, nor the gun gauge. I know the gauge works because it showed near 4500psi when filling. Leaves the valve far as I can tell. Also tried another whip on it. Same thing.
Anyone hear of such before? I'd just bought this valve a couple years ago and has seen light use.
pic shown to see the type of valve and tank.

valve.jpg
 
No spring in the check valve... I'm at a loss as well. Talked with Grackleblast who has a valve for me so will give that a go. I got the valve from PA a couple years ago and was advertised as a 'slow fill' valve and most of my guns that I was shooting at the time only filled to 3kpsi so I didnt pay it much attention. Then when I did notice it, I just grabbed another tank. Now it's irritating me enough to dive into it. But think Grackleblast las me squared up!