How exactly did you make the PDF, and how did you make it accessible? One thing I would try is viewing the document with a screen reader emulator like Callas Software's pdfGoHTML or the Screenreader Preview in PAC 2.
Via InDesign, following all the recommended ADOBE conventions.
Ive made many APDFs before, but now I have the same issue with another document Ive recently made up.
I've remade the Structure, checked all the tags, redone and checked all the images as Artefacts, I've ruled out my settings in Acrobat have changed or are faulty.
Im checking it in JAWs and both are now stopping on the first page claiming to only have one Heading and no links, these are large documents with multiple headings and links.
Ive checked against similar length document which have worked fine, and Ive remade some older documents with similar attributes to check if its something wrong with JAWs or my settings… every other doc works fine.
I'm currently going through them both forensically trying to find where or why they're not working.
It'll end up as something simple I guess, but its just finding it, what is annoying is that they both pass the accessibility check with flying colours, but then fail to work in an actual reader!!
I'll look into Callas Software's pdfGoHTML to see if it can weed out something that Acrobat's accessibility engine can't find. thanks.