Playlists do not appear on USB key when connected to my computer

Hello, 

Long story short, my computer was stolen with all my music on it. Luckily for me, I still have a USB key where I used to export my music from Rekordbox to it, in order to play on CDJ. 

However, when I connect this USB to my new computer, the playlists do not appear: all my tracks appear, but none of my playlists.

I don't understand what I am doing wrong and I would like to know how I can access the playlists stored on my USB (so I can import them into Rekordbox without having to recreate all my playlists manually). 

Thank you in advance,