Did you have logs open? Anything about SmartStart?
I assume you clicked the Refresh List button in the app and it stays in pending?
If you already partially paired the device then it may not be going into pairing mode again. You may need to factory reset the device.
This would also be helpful to see the state of your zwave radio:
The very bottom of my post I linked to above has more through steps as well.
You might want to try this first:
Then this is the full instruction
