Poppet leaking when not cocked, the Hammer spring is pushing on the poppet, cocking it relieves the pressure of the hammer spring. Normal? but it happens. Just to make sure it's not the fill port valve, put some Silicone oil in the Hose on your filler device, about 5 drops should be good and fill the gun with air, blowing the oil into the gun and valve, then see if that solves the leak problem, sometimes O-rings get dry and need lubrication.