I have just updated Sharepoint from 2013 to 2019 and all is well except for PDF integration. In Sharepoint 2013, users can open PDF files directly from SharePoint in Acrobat reader and check it out and comment the file. When they save it, it saves it back to SharePoint.
In 2019, when I force the system to open the PDF in Acrobat, it opens a local copy so the user needs to upload the file back to Sharepoint.
I've tried multiple solutions from various sites including updating the DocIcon.xml file and running the following command in powershell
Get-SPWOPIBinding –Application "WordPDF" | Remove-SPWOPIBinding -Confirm:$false
Any help would be greatly appreciated