MS 4 hijacked MS 3 file association

After installing Musescore 4 the file type *.mscz is now associated with MS 4.
Using the typical Windows 10 repairs for this type of change is having no effect.

The typical repair is right click on a *.mscz file and Choose "Open With" browse to
C:\Program Files\MuseScore 3\bin\MuseScore3.exe
and then check the box "Always..."
but that is not working . . . except for the first time.

An other typical repair is using FileTypesMan.exe and fixing the association there
but FileTypesMan.exe shows the association to be MS 3
so it appears that MS 4 has something in it that keeps reclaiming the association.

If anyone has a fix for this I'd appreciate it.

Thanks!

Steve