could someone send me a file with one of those tags so i can see what is going on
Here is an mp3 file that contains metadata as Picard writes it:https://www.dropbox.com/s/m7lbi6i1b7mg2wd/Picard.mp3?dl=0
MP3tag shows musicbrainz_trackid, MusicBee doesn't:
Perhaps try Picard yourself?
There is a portable version available that makes it very easy to test it without altering anything on your system.
Considering MusicBrainz is currently by far the best option to retrieve metadata, it would be nice to see some enhancements in MusicBee to make the two (even) more compatible.
I believe having all MusicBrainz id tags available by default without the need to create (sacrifice) custom tags for them has been an outstanding wish for a while.