Beatgrid Updates from DB are not reflected on synched device RB 6.7.1

I have the Problem that Updated an saved Beatgrids in Rekordbox are not getting synched to USB Devices

Things done:

• Update a Grid
• synch device, include playlist with changed Track
• check on Player -> old Grid is shown
• Check in DB, Grid look excellent
• Synch via Drag & Drop (whole Playlist) 
• check on Player -> old Grid is shown
• Check in DB, Grid look excellent
• Format USB Stick in FAT32
• Close and re-open Rekordbox
• Synch whole collection to empty stick
• check on Player -> old Grid is shown
• Check in DB, Grid look excellent
• check in RB via Devices -> my USB -> all Tracks -> Tracks to check -> this also looks perfect in Preview Player / Export Preparation Player

acutally i can´t understand how it is even possible that old Beatgrids get exportet to completly new Stick. I have the equipment (XDJ 1000 MK2) right here to test, but met also other djs on the weekend with similar Problems. 
Update 6.7.1 is 3 Weeks out now, I wonder if any other djs can check if they have the same problem. 
I run RB under Win10.

Thx Richarde