1) Create a new gameObject
2) Open the timeline window (Window->Sequencing -> timeline)
3) In the timeline window, click on Create
4) Click on the + button and add an Animation track
3) Drag an object from the scene to the track's object selector

Result: The track object selector shows None even though the object is bound (check in the PlayableDirector component to to see the object bound to the track)
Expected: The track object selector should be assigned to the object being dragged.