Description of issue
It seems that if the server isn't already running then OSVRTrackedDevice::activate() simply returns VRInitError_Driver_Failed right away. SteamVR-OSVR hence needs the OSVR server to be started before SteamVR.
On the other hand, everything will work correctly if you restart the OSVR server after a correct initialization.
Steps to reproduce the problem
Start SteamVR.
Start the OSVR server.
See that the status doesn't get to ready.