Unity multiplayer development for the Rift

I've been watching tutorials and started making my game multiplayer with photon.

When I'm running my game in multiple instances to test for multiplayer, I have all my player and camera prefabs disabled by default and I reactivate them for the instantiated player only. The player that creates the room works just fine but the next player, the left and right cameras don't respond to the headsets movements and I get the "No Sensor Detected" message.

Is this a result of trying to run 2 instances of the game with one headset? Unfortunately, I only have 1 rift so I really hope I don't need 2: (

Any help would be greatly appreciated! Much thanks!