@Pakiza first thing is to run an internet speed test like Fast.com as there are other resons for web pages to lag than the speed of your connection. Once you know the speed to the device then check the speed to the hub which is easily done by checking the speed shown in the My Sky app's service checker. If yhere is an issue there the app should offer help.
However it is very common to have high speeds at the hub but lousy speeds on devices connected by WiFi as in many homes the layout and type of construction means a single hub cannot provide usable wifi in every room.
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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
