With multiple Preview assets on one bone, only one appears in Skeleton Tree

With multiple Preview assets on one bone, only one appears in Skeleton Tree.

Regression: YES

Working: 4.13.2 CL:3172292
Broken: 4.14.1 CL:3224400

1. Create a Third Person Project
2. Open the Mannequin Skeletal Mesh in Persona
3. Got to Window>Skeleton Tree
4. Right click on Hand_L>PreviewAsset>Sphere
5. Right click on Hand_L>PreviewAsset>Cube

Result: In the Skeleton Tree, only Sphere shows up, even though the Cube is visible in the viewport
Expected: Two Meshes show in the Skeleton Tree Hierarchy under Hand_L

Second Preview mesh vanishes