Start small. Pick one real example where the chatbot failed and follow the information from the original document to the final answer.
Find out where things went wrong before making changes.
Once you've identified the problem and applied a fix, test that same question again. Then try other questions that depend on similar information.
It's important to check that solving one problem hasn't created another.
And remember that sometimes the correct behavior is for the chatbot to say it doesn't know.
If the information is missing, contradictory, or restricted to certain employees, the chatbot shouldn't invent an answer or expose information the person isn't allowed to see.