JMenu looks weird when using jgoodies-looks WindowsLookAndFeel

Question

So I've been trying to give my Java Swing application a native Windows look using JGoodies-Looks' 2.7.0 Windows L&F, but stumbled upon a problem while trying to create a JMenuBar, as it looks weird. What am I doing wrong?

This is how a JMenu looks in jgoodies-looks demo:

And this is how it looks in my demo app:

Please Note: the first JMenuItem is howevered

Demo code:

import com.jgoodies.looks.windows.WindowsLookAndFeel;
import javax.swing.*;

public class TestForm extends JFrame {

    public static void main(String[] args) {
        try {
            UIManager.setLookAndFeel(new WindowsLookAndFeel());
        } catch (Exception e) {
            System.out.println("Can't change L&F: " + e);
        }
        SwingUtilities.invokeLater(TestForm::new);
    }

    public TestForm(){
        this.setBounds(200, 200, 500, 500);
        this.setTitle("Test");
        this.setJMenuBar(constructMenuBar());
        this.setVisible(true);
    }

    private JMenuBar constructMenuBar(){
        JMenuBar menuBar = new JMenuBar();
        menuBar.add(constructEditMenu());
        return menuBar;
    }

    private JMenu constructEditMenu() {
        JMenu menu = new JMenu("Edit");
        menu.add(createItem("Copy"));
        menu.add(new JSeparator());
        menu.add(createItem("Paste"));
        return menu;
    }

    private JMenuItem createItem(String title){
        return new JMenuItem(title);
    }
}