@mehmet+Bekir are you measuring the speed on a device connected by WiFi or on the service checker in the My Sky app. If the former the issue could be either poor wifi in your home or an issue with the line to your hub. You need to identify where the issue is as Sky can do little about the former except sell you their WiFi Max package annd provide extenders. The speed you the hub requires action by Openreach which Sky can sort for you.
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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
