Fixed Joint added to gameobject through script during gameplay not showing up until game stopped

I am developing for the Vive using the steamVR tookit prefabs in Unity. I have a rigidbody on the camerarig. When I add a fixed joint to the camerarig via script during gameplay, it does not show up in the inspector, or take effect, until I stop running the game simulation within Unity. It will then be in the inspector, and if I launch the game within Unity again, the joint will be in effect. What could be causing the joint not to show up initially?