scnview.overlaySKScene with scene from file causes view to render continously

If I add an SKScene overlay it causes my scene to render continously at 60fps when there are no changes. the rendercountinously option is set at it's default (false) and the overlays .isPaused is set to true. Also there are no actions running on either the SKScene or SCNScene


If I create an SKScene in code, add a few child nodes and us it as the overlay. Everything behaves as expected. The view only renders when there is some change to my scene.


Is this maybe a bug?