I used the online tool to create a 15V / 230mA out design using the Viper06LS and followed the same including the components suggestions. The circuit seemed to perform almost perfectly and the output was consistent. I made 5 boards and they all worked fine.
However after a while on one of the boards the circuit has gone into the overload condition (50ms / 1sec) condition. Now I have removed the load (just an LED now) and still the issue remains. I have even replaced the Viper06LS with a new one and the situation is the same.
Attached is the design from the online tool. I have replicated the same exactly.