@Llliii your post is confusing if you have Sky broadband you have no connection with EE which is the Broadband and Mobile brand name for BT group do you mean Openreach engineers by any chance? Although Openreach are owned by BT it is an entirely separate operation who operate the network Sky and EE use?
Where are you seeing the security warning and what did it say? Sky's broadband is secure by which I mean the default WiFi security on the hubs is at least WPA2, Sky update the hub's firmware regularly to deal with new threats and Sky's backhaul network meets or exceeds industry standards. Occasionally devices (especially newerApple devices) do give security warnings but these can be safely ignored once understood.
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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
