Checkbox initialization delay Java FX 8

Can someone tell me why there is a delay on Checkbox initialization with my Code?

What happens is that if I open the program, I have to click the Checkbox several times until it performes the desired Action.

The Controller also contains setter and getter methods.

Thanks a lot

public class Controller {

   /* Defined variables */

    @FXML
    private CheckBox happyboxtick;


    @FXML
    private VBox topbox;

    @FXML
    private VBox designbox;

     @FXML
    public void initialize(){

    happyboxtick.setSelected(true);

        designbox.setVisible(false);
        designbox.getChildren().removeAll();

        topbox.setVisible(true);
        topbox.getChildren().addAll();

    }


@FXML
    public void doSomething(ActionEvent e) {
        //final CheckBox chk1 = new CheckBox("chk 1");
        //final CheckBox chk2 = new CheckBox("chk 2");
        EventHandler eh = new EventHandler<ActionEvent>() {
            @Override
            public void handle(ActionEvent event) {
                if (event.getSource() instanceof CheckBox) {
                    CheckBox chk = (CheckBox) event.getSource();
                    //System.out.println("Action performed on checkbox " + chk.getText());
                    //System.out.println(chk);
                    if(chk.isSelected()){
                        System.out.println("My box is selected.");
                        topbox.setVisible(false);
                        topbox.getChildren().removeAll();

                        designbox.setVisible(true);
                        designbox.getChildren().addAll();
                    } else
                    {
                        System.out.println("My box is not selected.");
                        topbox.setVisible(true);
                        topbox.getChildren().addAll();

                        designbox.setVisible(false);
                        designbox.getChildren().removeAll();
                    }/*
                    if ("Yes".equals(chk.getText())) {
                        chk2.setSelected(!chk1.isSelected());
                    } else if ("chk 2".equals(chk.getText())) {
                        chk1.setSelected(!chk2.isSelected());
                    }*/
                }
            }
        };

        happyboxtick.setOnAction(eh);

        //chk1.setOnAction(eh);
        //chk2.setOnAction(eh);
    }
    }

The Code compiles perfectly. Initialization works. The right Option is selected. But when I click the box, I may have to click several times until the Elements are shown. And I don't know why.