RBX duplicating "External/Music/Genre/Albums/Artist-Title/file.mp3" to "External/Contents/Artist/Title/file.mp3" - WHY!???

• ALL my mp3s are on an External SSD (in my own structure: External/Music/Genre/Albums/Artist-Title/file.mp3)

• I've created Rekordbox Playlists from mp3s on that External SSD

• I now SYNC those playlists (via Sync Manager) to that same External SSD (in order to plug it into my XDJ - as i want to be able to browse by playlist, artist etc)

Yes, the sync is successful.. I can now browse by playlist, artist, album, year etc etc... but it's also created a "Contents" folder off the root of External SSD and copied (duplicated) *some* files in there... right now, around 48GB worth!

Why is it doing that? EVERY song in those playlists resides on that same External SSD that I eventually synced the playlists to.

Why would it refer to some in their original location but others it copies to the Contents folder and refer to it there?

So confused (& annoyed as its wasting GB's worth of space).  HELP!