I recently had this issue, I wanted to use WiFi instead of ethernet because I wanted to move the router to a better location. I couldn't connect my SkyQ box to my NowTV hub via WiFi, it wouldn't recognise the WiFi password. After a lot of googling I couldn't find an answer but managed to solve it by trial and error.
What I did was, unplugged the ethernet cable, went into settings on SkyQ (settings-status-network connections) and pressed "Network Setup" then "reset".
When you see the options for what router your connecting to, before you choose, press and hold the WPS button on the router until lights flash. Then press "connect to Sky broadband WiFi"