Im not sure since when, but at least since the march update, my surface pro is not discovering my ptv3000. I also have a nexus 4 and thats working perfectly. Not sure if Microsoft broke something recently.
Netgear ptv3000. It's a widi/miracast receiver. It's a popular accessory for surface pro/2/pro 2 users. Hook it up to your tv and you can wirelessly mirror your laptop to your tv. But it's always been a bit quirky with surface support