Well any mechanical clicking can only come from the solenoid valve, but why it is opening & shutting I cant say, however it should not have anything to do with leaks as the valve is a simple electric switch than opens when the power is on & auto shuts when power is off. If it is continuously opening & shutting then that suggest either a faulty power supply (timer) or a faulty valve!
The valve might not have enough power to open the tap & allow the gas through, that is why you need to turn down the pressure so perhaps the valve is indeed knackered!
The valve might not have enough power to open the tap & allow the gas through, that is why you need to turn down the pressure so perhaps the valve is indeed knackered!