Hi Williamr,
We're sorry for the trouble you had while using Adobe ExportPDF service, Please sign out from Adobe Reader, reboot the machine. Launch Adobe Reader back and sign in, then check for any pending updates of Adobe Reader from help>check for updates, reboot the machine after updating Adobe Reader and try exporting the PDF file.
The record shows that you are subscribed to Adobe ExportPDF service, and as you mentioned that you are able to access the service through the URL https://cloud.acrobat.com/exportpdf
If after updating Adobe Reader, you are still not getting the Export option, then use Acrobat cleaner tool to remove installed Adobe Reader Download Adobe Reader and Acrobat Cleaner Tool - Adobe Labs
Reboot the machine and install the latest version of Adobe Reader from Adobe - Adobe Acrobat Reader DC Distribution
For more troubleshooting, refer to Troubleshooting Create PDF, Export PDF, Adobe Send, Fill & Sign … services(PDFPack or Document Cloud Services).
Let us know how it goes and share your observation.
Thanks,
Anand Sri.
[Moving from Acrobat Reader to Document Cloud PDF services ]