Multi-Material Skeletal Meshes assigned a Material in Details panel lose access to all other materials

When you assign a Material to a Multi-Material Skeletal Mesh via the Mesh's Level Viewport Details Panel, you will lose access to all the other material Elements after the first assignment. For instance if your mesh has 5 Elements and you assign a material to Element 2 than Elements 3 and 4 will disappear.

This problem does NOT occur on Static Meshes with Multiple Material Elements.

1. Open QAGame Editor
2. Add QA_Assets/SkeletalMesh/Main_Player_Export to the level
3. From the Mesh's Level Details Window, add QA_Assets\Materials\Test_BlueMaterial to Element 0.

RESULTS:
Access to Elements 1 through 3 disappears

EXPECTED:
Still have access to all material slots