Hello Danielr,
As per the description above, you are not able to upload PDF files on Adobe PDF services due to the Norton Extension in the browser, Is that correct?
I have shared steps with you via Private message, please check your email inbox.
You may try to use the Adobe ExportPDF service through the URL https://cloud.acrobat.com/exportpdf and you can also use the service through the free Desktop version of Adobe Reader, to download the Reader, you can use the URL Adobe - Adobe Acrobat Reader DC Distribution
For more troubleshooting steps, you can refer to Troubleshooting Create PDF, Export PDF, Adobe Send, Fill & Sign … services(PDFPack or Document Cloud Services). Link: https://forums.adobe.com/docs/DOC-8841
Hope the steps shared in the private message helps.
Regards,
Anand Sri.