Terrain Wind is working in Scene View but not in Game View?

Hello, I am new to unity, and get the feeling I am missing something obvious here.

I've not had a problem with the Terrain or Terrain Wind before now, I don't know what happened, but for some reason when I run my game my Detail Mesh grass is not moving in the wind... However in the scene view, while the game is running, it is swaying around just fine!