RASA FormAction ActionExecutionRejection не выводит повторный запрос на отсутствие слота

Я пытаюсь реализовать здесь FormAction и переопределил метод проверки.

Вот код того же:

def validate(self, dispatcher, tracker, domain):
      logger.info("Validate of single entity called")
      document_number = tracker.get_slot("document_number")
      # Run regex on latest_message
      extracted = re.findall(regexp, tracker.latest_message['text'])
      document_array = []
      for e in extracted:
          document_array.append(e[0])
      # generate set for needed things and
      document_set = set(document_array)
      document_array = list(document_set)
      logger.info(document_set)
      if len(document_set) > 0:
          if document_number and len(document_number):
              document_array = list(set(document_array + document_number))
          return [SlotSet("document_number", document_array)]
      else:
          if document_number and len(document_number):
              document_array = list(set(document_array + document_number))
              return [SlotSet("document_number", document_array)]
          else:
              # Here it doesn't have previously set slot
              # So Raise an error
              raise ActionExecutionRejection(self.name(), 
                                             "Please provide document number")

Итак, в идеале, согласно документации, когда происходит ActionExecutionRejection, он должен произносить шаблон с именем utter_ask_ {slotname}, но не запускает это действие.

Вот мои шаблоны domain.yml

templates:
  utter_greet:
    - text: "Hi, hope you are having a good day! How can I help?"
  utter_ask_document_number:
    - text: "Please provide document number"
  utter_help:
    - text: "To find the document, please say the ID of a single document or multiple documents"
  utter_goodbye:
    - text: "Talk to you later!"
  utter_thanks:
    - text: "My pleasure."