Privacy error in ChatGPT, you know about this?

I was doing an assignment with chatGPT, so I uploaded a PDF to him, I asked him something about it and he gave me information from a PDF that he had never uploaded, so it was a privacy mistake, here is the evidence.
I'm unable to view the content of the link, but if you provide a description or key details, I can help summarize it in a sentence! (Captioned by AI)