Sorry for the delayed response and inconvenience caused. As per the description above, I can understand that you are not able to convert a PDF to Word as only part of PDF file is getting exported, Is that correct?
The record shows that you are subscribed to Adobe ExportPDF service, try exporting the PDF file through the URL https://cloud.acrobat.com/exportpdf with your Adobe ID and password on a browser like Chrome, or Firefox, or Safari and see if this brings any difference.
You can also refer and try the suggestions from the following Adobe article if you are getting similar error message File conversion error | ExportPDF
Have you tried any other PDF file? Is it specific to one PDF file or with all the PDF files?
If it is specific to one PDF file, Is it possible to share the PDF file with us? To share the file, please use Adobe Send feature, upload the file, share the link to files via private message only, How Do I Send Private Message
Let us know how it goes and share your findings.