Added Scene Components are Missing Billboard Nodes

Newly added scene components to blueprints will have no billboard sprites, and thus cause the actor to be invisible in the editor unless other visible components are added. They exist on the default root, but not ones added afterwards.

The problem seems to be because the new component's USceneComponent.bVisualizeComponent is 0 in the problematic case.

1. In content browser we create a blueprint that inherits from AActor, name it BP_MyActor.
2. Open BP_MyActor, add a new SceneComponent to this Blueprint in Components panel. For ease of observation, I also add a BoxCollision Component.
3. Drag the new SceneComponent upon the DefaultSceneRoot to make it be the new root (and according to hint, the default root will be deleted).
4. Compile BP_MyActor and save it. Drag it to the level. And you will find no Billboard Sprite for the BP_MyActor instance.