Acrobat Reader 2020 Classic will not set as default for .pdf files

[Guest]

We are using Acrobat Reader 2017 Classic right now.

But we want to switch to the new version 2020 classic.

With the Customization Wizard we have generated a .mst transform file.

By 'Installation Options' we set

To install the Acrobat Reader we using this commandline

msiexec /i <pathtomsi>\AcroRead.msi /qn /norestart TRANSFORMS=<pathtomst>\AcroRead.mst

After finishing the install I try to open an pdf file and get this message

If we uninstall the Acrobat Reader 2017 Classic before and then installing version 2020 all works perfectly.

So I think there is a problem with the uninstall routine during the installation.

Has anybody the same issue, or is there somebody from Adobe who could check this?

Thanks!