You're probably saving the files in a tag format that File Explorer doesn't recognize.
In any case, if the metadata is present in MusicBee and music metadata tagging software (mp3tag, Tag&Rename, etc.), does it matter that it doesn't show up in Explorer?
File Explorer is very basic and is not capable of reading and writing metadata as extensively as dedicated programs are, so it's not a good idea to rely on it for checking on and editing your files.