Build 91 - Starting task manager causes an interruption of canvas drawing

Just launched simple app ( attached )

If I lauch task manager by Cntr+Alt+Delete, red circle dissappears.


It worked fine on previous builds.


PS.

Can't see "attach file", so that's it...
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public class Main extends Application {

    Canvas canvas;

    final int W = 1200;
    final int H = 800;

    double x = 0;

    @Override
    public void start(Stage primaryStage) throws Exception{


        VBox root = new VBox();

        canvas = new Canvas(W, H);
        root.getChildren().addAll(canvas);

        Timeline t = TimelineBuilder.create().keyFrames(new KeyFrame(Duration.ZERO), new KeyFrame(Duration.INDEFINITE)).build();

        t.currentTimeProperty().addListener(new ChangeListener<Duration>() {
            @Override
            public void changed(ObservableValue<? extends Duration> observableValue, Duration duration, Duration duration2) {

                GraphicsContext gc = canvas.getGraphicsContext2D();

                gc.setFill(Color.BLACK);

                gc.fillRect(0, 0, W, H);

                gc.setFill(Color.RED);

                gc.fillOval(x, 300, 100, 100);

                x += 1.0;
            }
        });

        t.playFromStart();

        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(root, W, H));
        primaryStage.show();
    }


    public static void main(String[] args) {
        launch(args);
    }
}

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