Solution: Adobe Acrobat is not the Default Application for PDF files

Another application may take over as your default for opening .pdf files due to an update or software change.

To restore Acrobat to your Default .pdf application;

Click start and type “Default” without the quotes.
Select choose default apps by file type.
Scroll down to .pdf
Click the icon to change the default application.
Choose your installed version of Adobe Acrobat or Adobe Acrobat 2020.
PDF files should now show the Adobe icon and open directly in Acrobat.