Physical Material Masks do not work in non-editor builds

Physical material masks are not working as expected in cooked builds. Licensee reports that the mask data is empty at runtime.

1. Open the attached project. (Directions to reproduce this project are here if needed: [Link Removed]
2. In the Content Browser - open the level 000_Test/PhysMatMaskTest1
3. Run PIE -> note that the lines connecting spheres to the textured box correspond to the color of the texture (also used for the mask). The blueprint PhysMatMaskBP is setting the color based on the physical material hit in the mask.
4. Under Platforms, select Windows -> Develop,  UnrealClient then Package Project
5. Run packaged project, 

Result**

Lines connecting spheres to the box are all green.

Expected

Lines connecting spheres to the box correspond to the texture colors, indicating the reading the physical material mask succeeded.