L6-functional_conversation: Call to wikipedia is working but LLM doesn't use the context

Running the notebook ‘L6-functional_conversation-student’ produces different results from the video.
Although, chain correctly recognises that to answer the question “what is langchain?” it should call “search_wikipedia” and even the first fetched page is about Langchain but then it responses as

{'input': 'what is langchain?', 'output': 'I couldn\'t find specific information about "LangChain" in my search results. }

What is the reason?