Button : button border render not correctly

Run this code:
@Override
    public void start(Stage stage) throws Exception {
        BorderPane root = new BorderPane();
        Button button = new Button("Button");
        button.setFocusTraversable(false);
        root.setCenter(button);
        Slider slider = new Slider(1,5,1);
        slider.setValue(3);
        button.scaleXProperty().bindBidirectional(slider.valueProperty());
        button.scaleYProperty().bindBidirectional(slider.valueProperty());
        root.setTop(slider);
        
        Scene scene = new Scene(root, 300, 300);
        stage.setScene(scene);
        stage.setTitle(VersionInfo.getRuntimeVersion());
        stage.show();
    }