UE4 to Oculus Go - normal maps not working

I've created a sprite sheet with diffuse and normal map textures.  In UE4 in order to get paper2D sprites with normal map you have to use a material called something like Default Lit Sprite Material.  I copied it and have setup my flipbook animation of my sprites.  Looks very neat in UE4.  In both the main viewport and the flipbook animation viewport I can see the normal map working on the sprite.  In the flipbook viewport you can move a temporary light around by holding "L" to see the specular reflections of your normal map to verify.  When I launch this project to the oculus go the model appears flat and only the diffuse texture appears to be rendering on the sprite.  I've disabled all lights except one that is position off to one side of the sprite so it should draw and strong specular reflection from the right.  When I am in the Go and looking at the sprite all I can see is the diffuse map.  No specular accents describing the normal map.  At this point I don't know what else to do because there is no more documentation on this.