I’d recommend creating a problem ticket and then sending your project file to @Norm for review. Previously, I had a problem with the export of a pdf file in my one project. I had created a list of about a dozen text links to downloadable pdfs, and for some reason, the last pdf in the list would not export. I was able to get around the problem by adding another unneeded pdf after the last pdf and then turning off visibility to this pdf, which allowed the previous pdf to now be exported.
I created a ticket and sent in my project file, but haven’t yet heard back about a resolution. At the time, in my problem report I told Norm that I had a workaround and it was not a big deal to fix right now. I’m guessing he had higher priority issues to work on and that’s why I haven’t yet heard back.
It’s possible that my problem and yours are related. Or it’s possible that the bloc my pdfs are in was somehow corrupted, so I’m planning to recreate the bloc when I get a chance to see if the issue goes away. Maybe you could try to recreate the bloc your pdf is in to see if your problem goes away.
Good luck in resolving your issue.