@Kimberley0510 if other devices are connecting it is almost certain there is an issue with your phone not the Sky hub.
One issue we see regularly is phones seitching yo use mobile data when the user expects them yo use the wifi. This is caused by a setting many phones including iPhones havecturned on by default which is called something like WiFi assist where if the phone can get a faster connection using mobile data it will switch to that. If that describes your issue disable thst setting which on iPhones is st the bottom of the mogile settings page.
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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
