Xdj 700 Rekordbox Link doesn't work

Hi everyone ! Hope everyone can help... I bought 2 xdj 700 more than 2 months ago and I still can't use them as I should. I'm very disappointed... After trying everything found on internet ans solutions from Pioneer engineers (videos has also been sent), when I click on the "LINK" button on Rekordbox, none xdj 700 get linked. The 2 DJ players are detected (catched) by internet server (connected on a Switch) though. Pioneer engineers told SACOM (PIONEER DJ support society) to tell me to post something here so they Can help me directly. Hope to get answer soon because I can't accept having spent 1500 chf and not being able to use them as I want to (I bought them Especially to get my laptop library on the xdj 700) ! Jérémy Resplandy (Andy J)