FB messenger always run 2nd time with its 1st response back into the flow and cause error

How To
1

Hi guys, I manage to follow this Youtube tutorial and the flow running fine.

However, my problem is that the 1st module FB Messenger trigger always get triggered with its own answer.

So when I test sending text to the agent, it will respond fine… but it will start the next run right away with its own answer. Then Make will deactivate the scenario
Scenario has encountered an error while being processed. Fix the error or clear the queue.due to is: [400] OAuthException (#100) No matching user found FB Trace ID: AnDzjm3-tKXng1z0BA_TxjX.

Anylight from the room here?

Cheers,

Kris.