Can't get regulator to stabilize

[squaremile]

I'm new to kegging and am having some issues with my regulator. I forced carbed the keg, and an trying to get the beer to the correct serving pressure. I'm curious how many times you should have to vent and re-turn the knob before it will stay at the proper pressure? Basically I turn the knob to 12 (there is a delay in how the regulator reads to 12), then I wait 10m, and vent to see if it will return to 12. I've done this 6 times and cannot get it to go back to the same pressure yet. I'm very aware that this could be a user error and am looking for some advice. Or maybe the regulator is defective?

Taprite Dual Body with red knobs (new)
Keezer at 36 degrees
5' beer and gas lines
FWIW, keg is over-carbed and foamy

Thank you!

 

[jbb3]

Close the valve on your tank. Bleed the keg and the regulator of pressure completely. Turn the pressure control knob on your regulator all the way down (left). Open the valve on your tank. Slowly turn your pressure control knob up (right) until the low pressure gauge shows it's at the desired serving pressure. That should do it.