When on wifi, content not loading

[Njr27]

We cannot connect to WiFi on our phones. Well we can, and it says we have full WiFi bars but NOTHING will load, not Google, not any social media apps,

mobile banking nothing will work on our phones (both mine, partners and sons) when we're on WiFi even though it says we're connected, have checked on here and there says there is no problem with the WiFi connections. 
We have to keep switching our WiFi off just to load anything! 

any suggestions? This has been happening for 2 weeks now and is REALLY annoying!

[JC451]

No internet . Keep checking it says I have internet but I don't. So no tv nothing at all on a wet Sunday 

[Highlinder]

@Njr27  & @JC451  can you check the colour of the lights on the router when this is happening to determine what the fault is  please using the link below.

https://www.sky.com/help/articles/broadband-diagnostic-which-sky-hub