The issue is back!!
What I realized - the XDJ-1000 is connected with Ethernet and USB. In the Event that the USB link is selected, I got 2 Options: 1. The USB Midi Connection, 2. The USB stick from the other XDJ-1000.
Selecting the XDJ brings up the Setting acceptance Screen, it tells me how many tracks are on the stick but there is no database structure shown.
When pulling the USB plug of the Connection to the PC, the database structure of the USB stick appears and it is working.
It looks like having both link to another USB stick AND USB Connection to the PC may interfere each other - well at least the Connection to the USB stick.
Pioneer can you please look at this? Maybe a bug.
Thanks
Frank