RulePolicy weird behavior

I have only defined rules and provided them with sufficient training data. My problem now is that RulePolicy, although an intent has been recognised with, for example, 95%, still triggers the action_default_fallback every now and then.

For example, I have a rule “Deny”. If I now write “No” 3 times in a row in the chat, then I get the correct answer behind the intent “Deny” but the fourth time the action_default_fallback is suddenly triggered.

If I continue with typing “No” in the chat then at some point just an action_listen is triggered instead of action_default_fallback.

Is it possible to switch off this behaviour somehow?

recipe: default.v1

language: de

  - name: "SpacyNLP"
    model: "de_core_news_lg"
    case_sensitive: False

  - name: "SpacyTokenizer"
    "intent_tokenization_flag": False
    "intent_split_symbol": "_"
    "token_pattern": None

  - name: "SpacyFeaturizer"
  - name: "RegexFeaturizer"
  - name: LexicalSyntacticFeaturizer
  - name: "CountVectorsFeaturizer"
  - name: "CountVectorsFeaturizer"
    "analyzer": "char_wb"
    "min_ngram": 1
    "max_ngram": 4

  - name: DIETClassifier
    epochs: 100
    constrain_similarities: true

  - name: EntitySynonymMapper

  - name: FallbackClassifier
    threshold: 0.6
    ambiguity_threshold: 0.05

  - name: RulePolicy

After changing every possible setting I found out that my mysql trackerstore is causing the problem. As long as I use the memory trackerstore everything is fine but as soon as I switch back to my mysql trackerstore the problem starts occuring again.

   type: SQL
   dialect: mysql+pymysql
   db: trackerstore
   username: basic_rasa_user
   password: xxx

Switching to postgresql fixed my problem. Don’t know what exactly is broken with mysql/pymysql.

  type: SQL
  dialect: postgresql
  url: rasa_trackerstore_server
  db: rasa_trackerstore
  username: postgres
  password: xxx