The user has attached a small project at the link to demonstrate the issue. Occurs in 4.5.1 and well as Main (//depot/UE4/Promotable-CL-2239587).
1. Launch: UE4Editor.exe
2. Create a new First Person Blueprint template project
3. Drop a static mesh into the level with Simulate Physics enabled
4. In the Level Blueprint, add a key input node
5. Cast to MyCharacter for the Mesh1P component
6. Get a reference to the static mesh
7. Set Simulate Physics for the static mesh
8. Attach Actor to Component
9. Use the Mesh1P component as the InParent input
11. Use the key input
Head over to the existing AnswerHub thread and let us know what's up.