Devices not connecting to WiFi

[FMillar]

WiFi is showing as an option but no devices will connect. The iPad advices a different channel to use but I have tried restarting the router many times and still not working 

[JimM1]

@FMillar What are your hub lights showing you and which hub do you have.

This link providers information about the coloured lights on the various hubs
https://www.sky.com/help/articles/hub-lights-explained-start