Link Cue Not Working

All of a sudden, my Link Cue no longer works.
I can listen fine through my headphones when I select the individual channel cues but I can't preview tracks anymore through the headphone with Link Cue.

Also, the headphone icons doesn't show on the mixer icon;

Why is this?

Same when using v5 and v6.
Nothing has changed is hardware or settings.

EDIT:
I turned off WiFi and it worked! WTH..?