When you have several radiobuttons which belong to one buttongroup you can move the selection with help of arrow keys, but when selection is changed only ItemListener get notified.

Expected behaviour:
ActionListener should be notified as well

This test shows the problem:

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.ItemListener;
import java.awt.event.ItemEvent;

public class TheBug {
    public static void main(String args[]) {
        JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        
        frame.setLayout(new FlowLayout());
        JRadioButton one = new JRadioButton("One");
        final JRadioButton two = new JRadioButton("Two");
        
        two.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                System.out.println("PossibleBug.actionPerformed");
            }
        });
        
        ButtonGroup group = new ButtonGroup();
        
        group.add(one);
        group.add(two);
        
        frame.add(one);
        frame.add(two);
        
        one.addItemListener(new ItemListener() {
            public void itemStateChanged(ItemEvent e) {
                System.out.println("PossibleBug.itemStateChanged");
            }
        });
        one.setSelected(true);

        frame.setSize(new Dimension(300, 200));
        frame.setVisible(true);
        one.requestFocusInWindow();
    }
}