i used to run in at 39psi the last month or so im running it at 55 or even 60 sometimes....,its about a year old now got it from gardiners.
its not an air lock maybe calibration? but i did set it at 30 CAL for ages it didnt seem to fix it for ,
could it be that the battery or pump on the way out?
batt is about 2 years old now but my last one was 6 years old.