WiFi not working despite "good signal"

[Stewmag82]

I've recently got ultrafast broadband and all was working until last night. Suddenly no apps will connect on phones, WiFi is non existent in the house despite checks on my account showing good signal to the hub and no issues in my area. 

I've rebooted the router several times with no avail. 

I've sky glass and ultrafast and have only had it around a month. 

I had no issues until last night when it suddenly stopped. 

I can't find any reason for it. 

[Gee4]

Same issue here just upgraded last week to ultra fast and service checker stating everything ok but no connection to TV or devices