Pro dj link problem

hi there
I Connect 2 X cdj2000nxs + 1x djm 2000nxs2 with LAN switch and then usb cable from cdj to laptop usb port. When pressing "link" on rekordbox, sometimes link doesn't work and appear "autorizza collegamento da cdj" message.
Sometimes I solved by turning off my laptop, sometimes by re plugging eternet cables on cdjs/mixer. I use original pioneer cable and tp link/d link switch eternet LAN.
Please help
Tks