i've noticed you can't see all the tags present in a file from MB
Just FYI the only external tagger I've seen that will display all tags a file contains simultaneously and their contents, without having to adjust the tag reading options, is
Kid3. For example, if you end up with a file with id3v1, id3v2, and APE tags, all 3 will be displayed open in their own window, where their contents can be edited separately or the entire tag deleted using the "Remove" button. I keep it on a toolbar button in MusicBee and do 90% of my editing through it. Of course, a file rescan is needed for MusicBee to pickup the changes.