I'm assuming you are using GPT-3.5 hey?
This is a prompt engineering problem. It's talking about context because the prompt templates talk about context.
GPT-3.5 is pretty bad at following more complex instructions, so it may take some fiddling around.
You can set the templates like this:
index.as_query_engine(text_qa_template=my_qa_template, refine_template=my_refine_template)
And you can use the existing templates as a reference for how to create your own
Here's the QA template (for chat models, this gets automatically transformed into a single human message):
https://github.com/jerryjliu/llama_index/blob/18d2ecbefcf5811f3a8b367931a5f1c28f6c2ac6/llama_index/prompts/default_prompts.py#L98Here's the refine template (specifically for chat models)
https://github.com/jerryjliu/llama_index/blob/18d2ecbefcf5811f3a8b367931a5f1c28f6c2ac6/llama_index/prompts/chat_prompts.py#L12