Man, that sucks. It's really annoying how sycophantic these companies have made their chatbots, which makes this worse.

But, I think by the very nature of how chatbots work, you can't fix that problem. Chatbots simulate what text is likely to follow other text.

If someone online has definitely read a book that really exists, and they describe a scene they remember from that book, the clear pattern online is that someone will say "Oh yeah, that's the book X by author Y". Some people might say "I've never heard of that book", but it's likely they might just not say anything. If we're looking at a kind of forum with upvotes and downvotes, the person who found the real book will be the most upvoted.

So, that's the pattern the LLM trains on. It knows that when someone posts a question like that, the best answer is one where someone names the book and types out the passage in the book.

It would be nice if the chatbot would instead say "I don't know that book" or "That book doesn't exist".

But, it can't do that, because it doesn't "know" anything. Everything the chatbots put out is a hallucination. It's just that some hallucinations are more useful. It has been trained millions of times on patterns when the passage someone remembers is "It was the best of times, it was the blurst of times", so when it hallucinates about that sequence of words, its hallucination is bound to be more helpful. But, if what someone remembers doesn't exist, or is obscure enough that it's not in the training data, things break. Then it follows the general pattern used for every other book, and comes up with a "useful" answer that doesn't match any actual book.