Raytraced mirror missing fog

I have Ray Tracing enabled for reflections. My mirror material is a very simple white Base Color, 1 Metallic and 0 Roughness. I have an HDR and Exponential Height Fog components with Volumetric Fog enabled.

As you can see from the attached images there is no fog being rendered in my mirror!

I tried adding a Sphere Reflection component and baking reflection maps but no difference. Since my mirror geometry is attached to a moving vehicle I have made it Movable.

The only thing disabled in my Reflection - Ray Tracing settings is ‘Include Translucent Objects’ as it introduces artifacts.

Can any Ray Tracing or reflection experts help?


rayTrace_reflectionSettings.JPG

r.RayTracing.Reflections.HeightFog 1

Is the skylight stationary? There’s also ‘Stationary skylight supports height fog’ in Project > Rendering settings.

ok thanks!