Branching by slot values not working

Hi, I have a bot which is supposed to reply differently based on which button that user clicks. But I am not sure why sometimes it happens that the bot didn’t give respective response based on the slot values linked to each button and I have to implement in custom action by checking slot value first and then triggering corresponding reply by FollowupAction. The only reason that I can think of for now is I wrote training stories for those options of different amount, which might result in unbalancing issue. Could someone help?

class ActionReplyAccessibilitySelection(Action):

    def name(self) -> Text:
        return "action_reply_accessibility_selection"

    def run(self, dispatcher: CollectingDispatcher,
            tracker: Tracker,
            domain: Dict[Text, Any]) -> List[Dict[Text, Any]]:

        if tracker.get_slot("accessibility_option") == "readability":
            return [FollowupAction("action_readability")]
        elif tracker.get_slot("accessibility_option") == "simple_language":
            return [FollowupAction("utter_simple_language_reply")]
        elif tracker.get_slot("accessibility_option") == "sign_language":
            return [FollowupAction("action_trigger_sign_language_screen")]
        elif tracker.get_slot("accessibility_option") == "volume_adjustment":
            return [FollowupAction("action_trigger_volume_screen")]
  utter_accessibility_options:
  - buttons:
    - payload: /select_accessibility_option{{"accessibility_option":"readability"}}
      title: 1. Lesbarkeit
    - payload: /select_accessibility_option{{"accessibility_option":"volume_adjustment"}}
      title: 2. Lautstärke
    - payload: /select_accessibility_option{{"accessibility_option":"sign_language"}}
      title: 3. Gesten- und Gebärdensprache
    - payload: /select_accessibility_option{{"accessibility_option":"simple_language"}}
      title: 4. Einfache Sprache
    text: Hierfür gibt es verschiedene Wahlmöglichkeiten
entities:
- accessibility_option
slots:
  accessibility_option:
    type: categorical
    influence_conversation: true
    values:
    - readability
    - sign_language
    - simple_language
    - volume_adjustment
- story: select readability
  steps:
  - action: utter_accessibility_needs
  - intent: affirm
  - action: utter_accessibility_options
  - intent: select_accessibility_option
    entities:
      - accessibility_option: readability
  - action: action_reply_accessibility_selection
  - action: action_readability
  - intent: continue_dialog
  - action: utter_readability_reply
  - action: action_accessibility_is_done
  - slot_was_set:
    - accessibility_is_done: true
  - action: utter_ask_customer_account