Hi I have a big problem with a jittery cursor when I use my SP4 with the type cover touchpad. I use the SP4 with the Surface Dock running the latest firmware. I need more USB connections than provided by the Dock and so I am trying a powered USB hub (this one: https://www.amazon.co.uk/gp/product/B0177AF0KK/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 ). I also bought a 10w 5v 2A power supply to use with the hub. This all works but has resulted in a jittery cursor with the touchpad. It is fine when the hub is removed but comes back if the hub is reconnected either to the dock or directly to the SP4. Does anyone know a powered USB hub that works for them? It needs to be powered because I need to connect external hard drives. Thanks in advance!