Benjamin Cayden gun gauge vs. pump gauge

I got out my 0.22 Cayden yesterday and found that it lost all it's air over the winter. So I pump it up to 2800 psi per both my pump and gun gauges and found a leak from around the threads of the foster fitting. I took the fitting off and wrapped teflon tape around the threads and pumped it back up to 2800 psi per my pump gauge and checked the fitting and found no more leak, yay!! But then I looked at the gauge on the gun and it only showed 2000 psi and seems to be holding steady at that pressure. Why would this happen all of a sudden? The gun gauge worked fine until I wrapped the foster threads to fix the leak. Thoughts???
 
I got out my 0.22 Cayden yesterday and found that it lost all it's air over the winter. So I pump it up to 2800 psi per both my pump and gun gauges and found a leak from around the threads of the foster fitting. I took the fitting off and wrapped teflon tape around the threads and pumped it back up to 2800 psi per my pump gauge and checked the fitting and found no more leak, yay!! But then I looked at the gauge on the gun and it only showed 2000 psi and seems to be holding steady at that pressure. Why would this happen all of a sudden? The gun gauge worked fine until I wrapped the foster threads to fix the leak. Thoughts???
I have a Kratos and an Akela. A friend has a Kratos. None of the on-board gauges agree with any other gauge either of us has available. I sometimes want to replace the really, really cheap factory gauges but, most times my attitude is "why bother."

JackHughs