I hope to be able to describe my problem in a reasonably comprehensible way.
To explain for now: I also tag my files with the singers. For this “Vocals” tag I use the “wwwartist” field.
I wanted to change something a few days ago in an already tagged album and opened it in mp3tag. I noticed that there were no entries in the field for “Vocals.” If several singers were listed, there was only one left.
So for example:
Instead of “Anna Zanoda; Gerhard Brian”
There was only “Anna Zanoda” in mp3tag.
Even in "extended tags" window was only one tag for Vocals.
But: In musicbee there are still “Anna Zanoda; Gerhard Brian”
How is that possible? Even when I close and reopen musicbee, search for new files, update database ect. It's still the same. When I change the tag in mp3tag it is changed within seconds in musicbee also.