Which action will be used for max confidence in RASA?

Which action will be used for max confidence intent in RASA? How can I handle these intents?

Example: user input “/start” and I found intent name is “start” and confidence = 1.

In previous version, the confidence is 0 and I can handle it in fallback action. But now, maybe it not run into fallback action anymore.

My RASA core is 0.13.2.