Realtime lights stop illuminating on scene load, Unity 5.4.2f2

[Overswarm]

In Unity 5.4.2f2, the valve shader isn't illuminated by realtime lights, but only after scene load and only if there are shadows involved.

The screenshots attached show a scene on first run, then the same image on loading a new scene, then the same image on the new scene after turning off shadows on the torch.

I've been able to get lights to work by: -switching shaders -switching the 'receive shadows" to 'off' on the valve shader material -turning off the shadows on the torch

I've been unable to find anything else causing the issue. Even loading a duplicate of the same scene is broken on scene load!

Loading has been done via SceneManager.LoadScene and SceneManager.LoadSceneAsync, both single and additive. Same issue in all loads.

Does anyone know a fix for this? Shadows are pretty important for my game.