@Helen334 which type of Sky TV system doyou have SkyHD+, Sky Q or Sky Stream? Each is quite different. If you other devices are staying connected it doesn't sound like a broadband issue.
If your TV box is faulty Sky will replace Sky Q and most Sky Stream pucks if thry are lent. However the older Sky HD+ boxes and some of the first Sky Stream pucks were sold so will not be replaced but it is worth talking to Sky
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65inch Sky Glass, 3 Sky Streaming Pucks, Sky Ultrafast + and Sky SR213(white Wifi Max hub) main Wifi from 3 TP-Link Deco M4 units in access point mode
