I have a problem with slots in rasa open source version 3.6.9. After moving in my history, I see that the data of some slots is lost or set to None. I wonder if someone have had this inconvenient. How could I fix this?

Here is my history:

- story: buy ticket path 1
  steps:
  - intent: buy_ticket
  - action: utter_ask_event
  - intent: provide_event
  - action: action_utter_provide_event
  - slot_was_set:
    - event_found: True
  - intent: affirm
  - action: utter_ask_quantity
  - intent: provide_quantity
  - action: utter_ask_email
  - intent: provide_email
  - action: user_email_form
  - active_loop: user_email_form
  - slot_was_set:
    - requested_slot: user_email
  - active_loop: null
  - action: action_utter_provide_price

And slots:

slots:
  event:
    type: text
    mappings:
    - type: from_entity
      entity: event
  quantity:
    type: float
    mappings:
    - type: from_entity
      entity: quantity
  event_found:
    type: bool
    mappings:
    - type: from_entity
      entity: event_found
  season_zone_id:
    type: float
    mappings:
    - type: from_entity
      entity: season_zone_id
  user_email:
    type: text
    mappings:
    - type: from_entity
      entity: user_email
forms:
  user_email_form:
    required_slots:
    - user_email

When I get to action user_email_form, I do have None in event, event_found and season_zone_id, these three slots were set in action_utter_provide_event.

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