regulator w/manifold driving me crazy

I have a dual regulator system, I use one regulator for carbing, and I use the other split three ways on a manifold for serving.

The serving regulator is driving me crazy. It just keeps going up slowly, so after about 5 hours, it's gained another 5 PSI or so.

I bleed the kegs, set regulator to 0 (unscrewed). Then, I slowly rotate screw so line pressure goes to 12 psi or so.

Unvariably, after a few hours, it's gone up to 15-18 psi. It is so annoying. I cannot figure out why it does this. I only have this problem with my serving regulator, not my carbing one.

you may have some gunk in one of the needle valves in the serving regulator, there is a clean out procedure to help with that. are your beers super carbed?

if you disconnect eveything from it, but leave it set at 12psi, how high will it end up after a day or two? (i think you may either need to dial it down further to accout for the pressure creeping up. or switch em)

sounds like you have an imperfect seal.

I had a Cornelius regulator doing that. I had to tap in the valve seats to fix it. Is there a weep hole on the cover? If so check for any leakage there. I could need a diaphram kit also.