Java CardLayout Show Problem

Ok me again i need help. For some reason when i click a button the button dissapears but not the panel

Here is the code:

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class MainMenu extends JPanel implements ActionListener{

ImageDirectory ID = new ImageDirectory();
PlayMenu PM = new PlayMenu();
JButton Play;
CardLayout CL;
Image BG;

    public MainMenu(){

    CL = new CardLayout(180,220);
    setLayout(CL);
    Play = new JButton("play");
    Play.addActionListener(this);
    ImageIcon BGSource = new ImageIcon(ID.Background);
    BG = BGSource.getImage();
    add(Play, "Play");
    add(PM, "PMenu");
    }

    public void actionPerformed(ActionEvent e){

        if(e.getSource() == Play){

            CL.show(this, "PMenu");
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        }

        public void paintComponent(Graphics g){

            g.drawImage(BG,0,0,500,500,this);
            }
 }

Here is the class that i tried to show when button is clicked:

import javax.swing.*;
import java.awt.*;

public class PlayMenu extends JPanel{

public PlayMenu() {}


}

It's probably working as it should. Your new PlayMenu is replacing the original MainMenu. Try adding setBackground(Color.RED) in the PlayMenu constructor to see if it does replace the previous MainMenu.