My internet is only working on certain tvs

[WhyWhy12345]

When my grandsons use there Xbox's cannot watch sky as  have no signal cannot get the bbc app on 2 of my tvs at all even when nothing else is being used it says the WiFi signal isn't strong enough it only shows 2 bars 

[GD1]

@WhyWhy12345  Have you tried the steps here?  https://www.sky.com/help/home/broadband/my-broadband-speed/improving-wi-fi-signal-to-my-devices/arti...