So I pay for the interenet and its not bad at 45mps and runs swimmingly until my girlfriend uses it in anyway. If shes watching videos on her phone or on netflix on the tv it runs annoyingly bad. So my question is, how do i make it so that i dont lag anymore. Can i prioritise my pc? I run on ethernet and shes using Wifi
You need a 3rd party router to prioritise your connection. Basic one is tplink 9970 about £40 would work ok
you cannot do it with hub
Its a common problem.
https://community.bt.com/t5/Home-setup-Wi-Fi-network/Low-BandWidth-High-Speed/m-p/1928959#M161274
https://community.bt.com/t5/Home-setup-Wi-Fi-network/Massive-lag-spikes-BT/m-p/1931086#M161641
And many more threads on this forum.
You can improve things by restricting the upload connection speed and priority of the streaming device, but not on the BT Home Hub.