So I'm having an issue with a new (to me) x-valve. When I air it up it fires once and then I can hear a small leak and the trigger pull seems to increase and it won't fire again. The first time this happened I de-gassed it and aired it back up, at this point it wouldn't fire and had the heavy trigger pull again. I degassed again but this time I pulled the trigger to reset the on/off pin just as you would to remove the valve, aired it back up and same as the first time, fires once, trigger pull increase, won't fire. I was able to repeat it this way multiple times

I thought it might be the bolt not quite resetting but I pushed back on it and it was seated so that wasn't the issue.

I then swapped valves with another gun and the problem valve had the same issue in another gun but the original gun had no problem with the other valve so I have narrowed it down to the valve and not the gun.

I thought about switching on/off's but I was getting low on air and figured it would be a waste of time. I suspect this has something to do with the on/off or the o-rings above it but I've never had this problem before so it's just a guess.

Any ideas?