Force BCE to only answer using document

I've been using BCE to summarize and answer questions about PDFs and one issue I keep running into is that every time I ask it a question it will respond like it doesn't know, try to pull something from the internet, or make something up. If I click on the suggestion "Answer from this page instead" it will give me what I need. The problem is that if I ask it another question, I need to wait for it to give me the garbage answer and then choose "Answer from this page instead" again. I've tried to give it instructions at the beginning of the conversation to only provide answers based on the page but it never seems to remember.

This issue means that for every question I ask, I am using 2 of the 30 responses I am allowed per conversation.

Edit: the best workaround I've come up with is to always include "in this doc" at the end of my question. This performs pretty reliably but it's still frustrating that it's required.