Filtering by metadata: what if no docs found? I want no hallucinations.

[artemdzyuba]

I have a Supabase-powered Conversational Retrieval QnA chain with a System message.

When metadata-filtered search returns no documents, the chatflow starts hallucinating. And I guess it's coming from the System message where his personality is given. I tried to add " If the question requires knowledge that are not found in the documents or if you didn't find any document, reply 'Sorry, I don't know' ". But that doesn't work.