Raytraced Hair Lighting using Light Functions atlas and positions the Light function material doesn't render correctly

Light functions don’t render on grooms when using ray traced shadows and positions in the light function material.

 

The setup: 

• A light (point/rect/spot) pointing to a groom hair system. 
• The light's "Cast Ray Traced Shadows" attribute is set to "Enabled" 
• The light have a light function material, using any position inputs. 

The problem: 

The hair system seems to not evaluate the light function at all.  

What we know: 

• The light function behavior changing when using any position input is totally normal.  
• The light function fallback from the light function atlas to the legacy method. 

1. Open the attached project
2. Enable and disable "Cast Ray Traced Shadows" on the problematic lights where the hairs aren't receiving the Light Function.

Expected

Light function renders the same whether position data is used or not

Actual

Light function doesn't render at all when position data is used, light is unaffected.