I've had my CDJ2000 Nexus' and DJM900 Nexus since the release time of the 2000's and only ever used the same Macbook Pro (2010) and i've never had an issue with linking my setup through a TP Link Switch (TL-SF1008D). It worked the very first time i tried it, right up until a few days ago.
Rekordbox is running V.2.0.7 and the CDJ's are on the latest V.1.13
The system worked when i was running the previous versions of Rekordbox and Firmware but i upgraded Rekordbox and that's when the issue appeared, i upgraded the firmware on the CDJ's and the issue still persists.
Attached are some pictures to show the issues, as you can see the CDJ recognises Rekordbox and the music in it but just won't load up anything, i've tried switching off wifi but i've never had an issue with wifi on. I have also tried connecting a single CDJ to the Macbook Pro (2010) and exact same issue happens.
Any input would help. Thanks
CDJ's recognising Macbook:
After selecting the above option you get this: