Static mesh created using a procedural mesh component does not appear to save

Creating a static mesh via the create static mesh button in a procedural mesh component creates a mesh that does not appear to save. If the editor is restarted the mesh asset is lost.

1. Download the attached project
2. Open the project
3. Click on the ProcMeshBP in the level
4. Select the Procedural mesh component in the details panel
5. Click the "Create StaticMesh" button
6. Click Save all
7. Restart the editor

Result: The static mesh that was created was not saved and is no longer available.
Expected: The static mesh asset that was created would have been saved and would still be available after restarting the editor