MAC regulators & solenoids bleeding air?

[Car_Wash_Guy]

They Ryko Soft Gloss uses MAC regulators & solenoids for control. I notice for sure that at least one of my regulators are always bleeding a bit of air. I even replaced it with a new one and it started to bleed shortly thereafter.

Is it normal for the MAC's to bleed air like that?

I also noticed that some, or most of the regulators are SENSITIVE as heck. Some also lose their setting over time. Is this normal?

Thanks!