UserWarning: Intent 'nlu_fallback' has only 1 training examples! Minimum is 2, training may fail

Yes will do that, I recently migrated from 1.x to 2.2.x, facing a lot of warning, stabilizing the model, and getting rid of them one by one.

This is a big blocker as I am not able to get the insight from rasa, had you faced this issue or any clue.