As above, it might be worth calling up BT. Maybe even lie about the poor wifi on the BT Hub and and they'll replace it to "fix" it (although honestly the HH3's wifi is pretty poor).
If that doesn't work then buy a gigabit switch: https://www.overclockers.co.uk/peri...ireless-lan/switches-and-hubs?sPage=1&sSort=3
If that doesn't work then buy a gigabit switch: https://www.overclockers.co.uk/peri...ireless-lan/switches-and-hubs?sPage=1&sSort=3