Windows 10 changes my default application from Acrobat DC Pro to Acrobat DC Reader

On my Windows 10 machine, I have set the default PDF application to Acrobat DC Pro. Each time I click a PDF file, it opens DC Pro. This works fine until I reboot my machine. At that point, the default PDF application switches to Acrobat DC Reader. So I change the default back to DC Pro, and again all is well until the next reboot.

Any suggestions?