Samuel,
I'm sorry to hear you were having a problem with the relocation; the process is supposed to work that if you moved the parent folder / directory containing your music, that the sub-contents would all be available since the structure of the tree hasn't changed, only the path to the parent folder. If you have made multiple moves, you'll need to make multiple relocation attempts.
If rekordbox is telling you that the files are already in your collection, then you have imported them from the new location and should delete those (located) duplicates, then relocate the missing entries.
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