refractive material - differing results in Blueprint preview VS in level


As you can see in the attached image, I have a sphere with a refractive material, and electrical patterns going in to the emissive channel. The material displays correctly in the blueprint preview window. However, when I place it in the world it only refracts the background object, it doesnt refract itself like it does in the preview.

So in level on the left, the background starscape is getting refracted, but the blue electrical currents are not. You can see in the preview on the right though that they do refract.

Any ideas why this might be?