No URL retrieving from my documents

I don’t know why, but this keeps stopping from working. I uploaded my PDF with links as a source, but when I ask in the chat for a meditation, the app gives me a non-existent link. It worked for a while, but now it doesn’t anymore. I also tried it with an Excel sheet, a Google Sheet, and that doesn’t work either. I don’t understand it at all, and I’ve been trying to get this working for a year already. Is this just never going to work? This is my app: https://mediteren.frankbruining.com