Unfortunately there is no out-of-the-box way to force the track ball to update. The track ball updates its content only when the mouse moves. I cannot suggest a work-around for this, using the TrackBallBehavior. Perhaps you can remove the track ball behavior and use annotations instead. I have attached a small project to demonstrate how this can be done.
I have logged this as a feature request in our PITS
where you can vote for it and track its status.
We are sorry for this inconvenience. Let us know if we can assist you further.
the Telerik team