Jerky camera motion/ aim on CameraRigRail

having an issue with a cine-camera on a CameraRigRail. I have the camera set to look at another actor. The camera moves along the spine fine but only rotates to look at the target aim actor once the camera hits that next frame. So it goes, move, aim, move, aim repeat and gives a very jerky playback.

I do not see similar behavior when animating a camera with simple keyframes. However attaching to this rail seems to break playback. Is this CameraRigRail only intended for capturing still frames? Why is the look-at behavior different?