Static imported as skeletal removing material IDs with some FBX

Static imported as skeletal removing material IDs with some FBX.

This user's FBX files are, so far, the only ones that exhibit this behavior

1. Download the attached zip file and unzip it
2. Import the box.fbx file
3. Uncheck Import as skeletal
4. Open the static mesh

Note: There are 5 Material IDs

5. Make a new folder and import the FBX again
6. Leave import as skeletal enabled
7. Change Normal Input Method to "Import Normals and Tangents" (otherwise this FBX will crash the editor [Link Removed])
8. Hit Import and open the skeletal mesh

Result: Skeletal mesh only has 1 material ID
Expected: Skeletal mesh has 5 material IDs