I think this is likely the culprit. maybe try bypassing each one individulaly starting with the one off the tank, to determine which one (if any) is faulty.
My guess is it is the one on the cutter, I seem to recall someone having an issue with a new Everlast cutter some months back that had a bad regulator from the factory. He seemed to suggest that Everlast knew they had a bad batch and was quick to send a replacement.
Edit, this is the one I was thinking of… it was an air solenoid not the regulator.
Try bypassing the regulators first… then if you can’t resolve it call Everlast and have them help you trouble shoot the problem.