Cubemap orientation fixed on device but moves in player or editor

I'm using a reflective shader on an object, with a cubemap providing the reflected texture. The problem I'm seeing is that the orientation of the cubemap is fixed on a device (iOS/iPhone or Android) but isn't in the editor or desktop player. For example, if you point the camera down (looking into -y), in the editor you'll see the top of the cubemap reflected back at you, but on the device you'll see the front of the cubemap reflected back.

I've added this here just to record it for folks having a similar problem - I reckon it's clearly a bug so I'll report it.