We have tried to reproduce the issue but we have been unable to, every time we try to uninstall Mp3Tag, it gets fully uninstalled with Uninstalr.
To confirm, can you tell me what edition of Mp3Tag are you trying to uninstall? There are at least three possibilities: The setup version and the portable version that are available at https://www.mp3tag.de/en/download.html and the software is also available via Microsoft Store. Do you remember which one of these do you have? This is important, because they are all installed (and uninstalled) in a different way.
Also, are you using Uninstalr 2.6?
