I recently installed a new low pressure switch on my well. The new switch is primed to cut off at 60 psi, and cut on at 40 psi. If there is a demand the pressure drops from 60 psi and over time down to zero where it remains until the demand is gone without cutting on at 40 psi. Once demand is gone the pressure rises to 40 psi without the pressure switch activating. Once it hits 40 psi the switch then turns on. Why is it not activating at 40 psi.