XDJ 1000 MK2 - Abnormal Time to load with link

Hello, I own two XDJs 1000 MK2. A problem occures while loading tracks from the link. On both decks when I load the tracks directly from the USB, there’s no problem and the tracks load at a normal speed. When I load tracks from the link one of the decks take a abnormal time to load the sec with the message NOW LOADING (many many seconds). I tried linking the two decks directly or with a link box, the problem is the same. I also tried with different keys, from different PCs/recordbox. My deck is still under garantee so I sent it back to Pionneer who was not able to detect or solve my problem. Has anyone encountered similar issues ?