We apologize for the inconvenience caused, as per the description above, you are not able to convert a PDF file using Adobe ExportPDF service, Is that correct?
The record shows that you have an active subscription to Adobe ExportPDF on your current Adobe ID, try exporting the PDF file using the URL https://cloud.acrobat.com/exportpdf with your Adobe ID and password on a browser like Chrome, or Firefox, or Safari.
Have you tried converting any other PDF file? try converting any other PDF file.
If the issue is specific to one PDF file, Is it possible to share the PDF file with us so that we can try it at our end? To share the PDF file, please use Adobe Send feature, and share the link to PDF file via private message only, How Do I Send Private Message