The dumb switch I'm replacing has three wires connected.  Ground, white, black.    Super simple.  However, when I connect the HS200 it powers up, I can control it from the app ( I hear the relay click inside the switch)  but the light does not turn on or off. 

I've tried these different wiring setups: 

ground to green, white to white / black to black

ground to green, white to black / black to white

Remove ground connect white to white / black to black

Light will not turn on or off in any of these situations.

When I twist the two wires (black / white)  together in the box the light turns on. Same if I re-attach the dumb switch. 

I'm stumped!  Any ideas?