@JonBashford first point make sure your new Sky hub is in the best possible position which is on a surface not on the floor and especially not under other kit. You maybe able need a longer Ethernet cable than the one Sky provided which can be buy bought from most supermarkets or hardware stores.
If at all possible link your PC to the new hub by a second Ethernet cable if you have to use WiFi if your WiFi card is over 5 years old it maybe buying a newer USB wifi adapter would help as very old wifi cards can be very slow. However I suspect your issue is signal strength. Your new Sky hub takes 24 hours to optimise so you may have more luck this morning
=========================================================
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
