[Gear VR - 4.9] Instanced Static Meshes are not reducing draw calls?

Hi All,

I have a hierarchical instanced static mesh component with 3 instances of a mesh in my test scene.
When checking the draw calls on PC in VR I get 2 mesh draw calls which is expected and 1 mesh draw call when playing from the viewport.

When running the same test scene on Gear VR (Note 4) mesh draw calls are 6 , which seems to show that the instance static meshes are not working.

This is killing my games frame rate as I use instances extensively and my draw calls are now reaching 170+ when before on version 4.7.6 in Gear VR they were between 30-40.

Is this a new bug in 4.9.2 or am I missing a new setting for Gear VR in 4.9 for instances?

Many Thanks!