Updating a meshes UCX collision in an FBX will not reimport with the updated collision if it's been removed

DESCRIPTION: When making a mesh with custom collision with the naming convention of UCX and exporting the FBX for use in UE4 the collision will import and update if any changes are made and reimported. If all collision is removed and only the mesh is exported and reimported into UE4 the collision will not be removed on import. You must manually remove it via the mesh editor

ATTACHED: Max file with UCX collision setup.

ENVIRONMENT:
OS: Windows 8.1
PROCESSOR: Intel(R) Xeon(R) CPU E5-2620 @ 2.10GHz
MEMORY: 32GB RAM
GRAPHICS: NVIDIA GeForce GTX 770

FREQUENCY: 3/3
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REPRO STEPS:

1. Create Mesh with UCX custom collision in modeling program
2. Import into UE4
3. Remove the UCX collision when re-exporting the mesh to FBX in your modeling program
4. Re-import into UE4

Expected: If the FBX is updated with no UCX collision and reimported the updated reimport will remove the collision

RESULTS: Currently, if collision is removed from the FBX that is updated the previous collision will remain.

WORKAROUND: Open the mesh in the mesh editor and remove the collision primitives manually.