MouseListener & MouseMotionListener don't work for JPanel with JComponents inside

I'm trying to drag JComponents which are inside a JPanel on a JFrame or better on the rootPane of the JFrame.

The JPanel which contains the components is using a horizontal BoxLayout.

When I run the code below I observed the following issues:

1. The MouseListener & MouseMotionListener are only working for the JLabel
2. The JLabel seems to be not visible
3. On trying to drag, the JPanel with the JComponents inside the JTextfield & JButton disapper once I hover over the location where the JButton was dragged it becomes visible again.

What am I doing wrong here? Such a little code and so many unexpected issues.

Please help!

Code to reproduce the issues:

import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

public class Main extends JFrame implements MouseListener, MouseMotionListener {
    private volatile int screenX = 0;
    private volatile int screenY = 0;
    private volatile int myX = 0;
    private volatile int myY = 0;
    private JPanel myPane;

public Main() {
    setSize(500,500);
    myPane = new JPanel();
    //myPane.setLayout(new BoxLayout(myPane, BoxLayout.X_AXIS));

    JTextField tf = new JTextField("Some text");
    tf.setEnabled(false);
    tf.setSize(110,20);
    JLabel l = new JLabel("°C");
    l.setSize(40,20);
    JButton b = new JButton("Button");

    myPane.setSize(new Dimension(tf.getWidth()+l.getWidth(), tf.getHeight()));

    myPane.add(tf);
    myPane.add(l);
    myPane.add(b);
    rootPane.add(myPane);

    myPane.addMouseListener(this);
    myPane.addMouseMotionListener(this);
}
public static void main(String[] args) {
    Main f = new Main();
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setVisible(true);
}

@Override
public void mouseClicked(MouseEvent e) {

}

@Override
public void mousePressed(MouseEvent e) {
    screenX = e.getXOnScreen();
    screenY = e.getYOnScreen();
    myX = myPane.getX();
    myY = myPane.getY();
}

@Override
public void mouseReleased(MouseEvent e) {

}

@Override
public void mouseEntered(MouseEvent e) {
    System.out.println("Entered");
}

@Override
public void mouseExited(MouseEvent e) {

}

@Override
public void mouseDragged(MouseEvent e) {
    // only move when edit mode selected
    System.out.println("Dragged");
    int deltaX = e.getXOnScreen() - screenX;
    int deltaY = e.getYOnScreen() - screenY;

    myPane.setLocation(myX + deltaX, myY + deltaY);

    revalidate();
}

@Override
public void mouseMoved(MouseEvent e) {

}
}