Vive Controller not enabled until mouse click

I'm a newbie to Unity and VR development. I'm trying to take a Unity FPS demo and port it to the Vive. I've been mostly successful but now i'm struggling with a few important details.

When starting the VR experience one Vive controller works (body movement) and the second one does not (trigger/fire & head/trackpad) until after one mouse click (which also fires). Once the mouse has been clicked the second controller has all functionality.

Like i mentioned, i'm a newbie and have parsed a lot of documentation (general Unity and VR) but know i'm missing something simple. I apologize in advance for likely missing something obvious but I've been struggling with this for about a week.

Any feedback or troubleshooting steps would be greatly appreciated!

Thanks!