Houston, we have a problem

[Certifried]

About 1.5 months ago, my humidity suddenly dropped by about 4%, so I turned the knob on my Cigar Oasis up and attained 65% once again. Yesterday, once again, my humidity dropped and was holding at 60%. I have turned the CO know all the way up, and we're holding steady at 62% now. I have filled the CO cartridge (both times) with distilled water first just to make sure it wasn't a dry cartridge problem. I would also expect the CO to turn on and stay on, which it hasn't done either time.

My question now is two-fold. I'm about to do the salt test on the hygrometer (western digital) and wonder what you think the problem will be: The hygrometer is going bad, or the CO is getting out of whack somehow. My second question is has anyone ever had this problem with the CO (which I think is the problem here) like this? I know I can send it to bargainhumidors and get fast and satisfactory service, I just hope that's not the problem.