Hmmmmmmm creeping reg maybe? As Reaper said, bring it to a chrony. Shoot it slow but consistent and watch the numbers. If they seem high at first and then drop as you shoot........the reg may be creeping. If the numbers are all over the place that is also a sign.
You can also turn the reg into the off position(gently). Then try shooting the gun. If it feels like air is still getting into the system you have a problem.
As I understand it a common problem is people squashing the reg seat by turning the adjustment screw in too hard. If your reg seat is damaged, the regulator will creep, no matter how many orings you change.
It's all about the angles.