MP100L , VOUT not starting , VB and VD only 12V


We are evaluating the MP100L for supplying 12VDC to our timer circuit.
We have done the prototyping and started testing but we are facing issue that VOUT = 0V , but VIN at PIN#8 is 335VDC (235VAC INPUT) , VB and VD are showing only 12V but as per the datasheet min threshold is 13.4V. In our initial understanding main device in the internal block of MP100L not working fine , to confirm that issue we have feed the 16VDC externally at the VB and VD pin and now we could get 13VDC at VOUT. Could you please help us to understand the issue and suggest us if any fine tuning required.