Syncing playlists to USB with sync manager: updating not working

Hi guys!:)

I have a problem with the sync function of my usb sticks:

The situation:
I am using a well working USB (already synced and working with CDJs). I now make changes in iTunes, eg. renaming playlist folders or adding subfolders / playlists.
Example: folder1 with playlistA, playlistB as in iTunes is already synced and working on my USB. I now change in iTunes let's the names of folder1 to housemusic1 and playlist2 to deephouse.

The problem:
If I know try to update my USB by syncing the updated iTunes playlists in recordbox, I get the problem that BOTH the old pre-renamed folders/playlists etc are shown on the USB AS WELL AS the new order of folders/playlists as currently seen in iTunes.
Example: Now on my USB after syncing shows BOTH folder1 (the old name) AND housemusic1 (and the new name), as well as both playlist2 (old name) and deephouse (new name).

Question:
What can I do so that my USB ONLY shows the current order and names of my folders/playlists as in iTunes (and not the old order)?
Example: I want to only see the new names ie housemusic1 and deephouse without needing to completely erase the USB content and resync from scratch (that takes hours...)

Any help is highly appreciated!!
Thanks and best!:)