CAN'T SYNC UPDATED USB TO REKORDBOX 5.8.6 on PC

I have rekordbox  on 2 laptops (one laptop stopped working well, so i added rekordbox to new laptop).  Recently updated to 5.8.6.  I added new playlist/songs, synced with usb on both laptops).  Tried to sync usb with rekordbox on pc, but i can't get new playlist to sync/update rekordbox on pc.