GPT not working when PDFs are part of the 'knowledge'

Hi all,
I’m working on a GPT and’d like to use a few PDFs as part of its knowledge. The thing is, it completely breaks down any time I add a PDF.

I have a CSV file and a PDF in this example as part of the knowledge. It works when there is only the CSV, but it breaks when I add a PDF. It does not break because the PDF doesn’t work; the GPT completely breaks on any request.

Is anyone else experiencing something like this?

In this screenshot, what I asked does not interact with the PDF.