Drop shadow effect does not properly update with Timeline animations on child nodes

Set up a VBox that contains an animated Rectangle. Add a drop shadow effect to the VBox. Then the drop shadow does not update correctly. See attached image for this problem.

Here is the source code, which is also attached:



import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.builders.*;
import javafx.scene.effect.DropShadow;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.VBox;
import javafx.scene.paint.Color;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.util.Duration;


public class DropShadowBugTest extends Application {

    @Override
    public void start(Stage stage) throws Exception {
        Rectangle toAnimate;

        //It is necessary to enclose the animated rectangle with
        //a VBox that has the effect, to see the bug.
        VBox vBox = new VBoxBuilder()
                .children(
                        toAnimate = new RectangleBuilder()
                        .width(200)
                        .height(50)
                        .fill(Color.BLUE)
                        .stroke(Color.BLACK)
                        .build()
                )
                .effect(new DropShadow())
                .build();

        //setup an AnchorPane to contain this VBox
        AnchorPane anchorPane = new AnchorPaneBuilder().children(vBox).build();
        AnchorPane.setLeftAnchor(vBox, 10.0);
        AnchorPane.setTopAnchor(vBox, 10.0);

        
        stage.setScene(new SceneBuilder().root(anchorPane).height(300).width(240).build());
        stage.setVisible(true);

        Timeline timeline = new TimelineBuilder()
                .keyFrames(
                        new KeyFrame(Duration.valueOf(0), new KeyValue(toAnimate.heightProperty(), 50)),
                        new KeyFrame(Duration.valueOf(600), new KeyValue(toAnimate.heightProperty(), 200))
                ).build();
        timeline.setAutoReverse(true);
        timeline.setCycleCount(-1);
        timeline.play();


    }

    public static void main(String[] args) {
        Application.launch(DropShadowBugTest.class, null);
    }


}