I assume you're referring to the low pressure reading. How long has it been since you pressurized the system? It can take a little longer for pressures to equalize than you might think. If you can find no leaks, proceed as follows:
Check your regulator for an internal leak. Close the valve on the gas bottle. Close the quarter turn outlet valve on the low pressure side of the regulator. Pull the pressure release valve until both gauges read zero. Then, open the valve on the bottle for a few seconds until the gauge readings stabilize. Then close the tank valve.
If the low pressure slowly increases you have an internal leak allowing gas to move from the high pressure side to the low pressure side. If this is the case, the regulator can be repaired, but since the system is new there should be some warranty. Contact NB customer service to find out what your options are.