Wi-Fi lights all on but Wi-Fi not working on certain devices

[Fantabulous]

Hi everything is working ok with the broadband in regards to my phone and tv, other things we have connected like our security camera and my sons Xbox ( which is connected with an Ethernet cable going from the broadband box to his room upstaits which used to work and now is on and off keeps dipping in and out and we not sure why. The wife says everything is fine but then it just cuts out. In our package is there a maximum amount of things that can use Wi-Fi? It just seems odd that all the lights are on the box and it says all is ok yet it keeps not working? Any ideas what it could be please. 

[Chrisee]

@Fantabulous no limit on devices and tge newer hubs can support 40 or so without issue. I am somewhat confused as you say devices including your son's xbox wich uses ethernet are working OK then go onto say it is on and off. When the connection goes down what happens the leds on the Sky hub? These will help diagnose the issue see https://www.sky.com/help/articles/hub-lights-explained-start