Roughness rendering differently on Macs

The roughness value for Macs renders differently (less rough or glossy) compared to Windows. It also seems to render as expected within the Material Editor preview window, but when applied to an object in the scene, the roughness renders differently.

The user on the answerhub mentions "The issue looks like the roughness is scaled by 0.5"

1. Create new blueprint project from the launcher with starter content.
2. Open the Advanced_Lighting map.
3. Create new material with a base color of (1,1,1), a metallic value of (1.0), and roughness of (0.5).
4. Drag a sphere into the scene and apply the material.

Outcome The ambient cubemap seems stronger than it should be and the roughness value seems less rough compared to the same material on Windows.

Expected The material renders nearly identical to Windows.