It is operating as designed. Are you looking for the convenience of seeing both at once? Newer versions of the software offer better capabilities of seeing the interaction of the layout and data views. For example, ArcGIS PRO allows you to detatch them and view them side-by-side.
I don't think ArcScene has a layout view. Isn't it only a scene view (data view)? Or have you exported the scene to place it on a layout in ArcMap?
Pro is the way to go if you want scenes and layouts in one application in one document and want to view both the scene and a layout containing the scene at the same time.
