Java SWING. Не отображается компонент пока не наведешь на него мышкой

Создал класс Bone, наследником от JPanel. При его добавлении в другую панель не отображается пока не наведешь на него мышкой. метод paintComponent() перегружал, метод super.paintComponent(g) вызывал. Но все равно остается та же проблема.

public class MainFrame extends JFrame {

MainFrame() {
    setTitle("Домино");
    setSize(new Dimension(1920, 1080));
    setLocationRelativeTo(null);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLayout(new BorderLayout());
    //setResizable(false);
    setExtendedState(JFrame.MAXIMIZED_BOTH);

    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 7; j++) {
            Image img = null;

            Singleton.getCollections().getBones().add(new Bone(img,i,j));
        }
    }
    System.out.println(Singleton.getCollections().getBones().size());

    JPanel south = new JPanel();
    JPanel north = new JPanel();
    JPanel west = new JPanel();
    JPanel east = new JPanel();
    GamePanel center = new GamePanel();
    south.setPreferredSize(new Dimension(1620, 150));
    north.setPreferredSize(new Dimension(1620, 150));
    west.setPreferredSize(new Dimension(150, 780));
    east.setPreferredSize(new Dimension(150, 780));
    south.setLayout(new FlowLayout());
    for (int i = 0; i < 8; i++) {
        Bone forSouth = new Bone(null, 1,2); //Тут создаю компонент.
        forSouth.setBackground(Color.RED);
        forSouth.setPreferredSize(new Dimension(80, 130));
        forSouth.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseEntered(MouseEvent e) {
                forSouth.setBackground(Color.WHITE);
                System.out.println(center.getSize());
            }

            @Override
            public void mouseExited(MouseEvent e) {
                forSouth.setBackground(Color.RED);
            }

            @Override
            public void mouseClicked(MouseEvent e) {
                south.remove(forSouth);
                south.repaint();
                south.doLayout();
                center.add(forSouth);
                forSouth.setBounds(center.getWidth() / 2 - 50, center.getHeight() / 2 - 50, 56, 91);
            }
        });
        south.add(forSouth); //Тут добавляю его в панель.
    }
    for (int i = 0; i < 8; i++) {
        JPanel forSouth = new JPanel();
        forSouth.setBackground(Color.RED);
        forSouth.setPreferredSize(new Dimension(80, 130));
        forSouth.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseEntered(MouseEvent e) {
                forSouth.setBackground(Color.WHITE);
            }

            @Override
            public void mouseExited(MouseEvent e) {
                forSouth.setBackground(Color.RED);
            }

            @Override
            public void mouseClicked(MouseEvent e) {
                north.remove(forSouth);
                north.repaint();
                center.add(forSouth);
                forSouth.setBounds(751, 326, 91, 56);
            }
        });
        north.add(forSouth);
    }
    //west.setLayout(new BoxLayout(west, BoxLayout.Y_AXIS));
    for (int i = 0; i < 15; i++) {
        JPanel forSouth = new JPanel();
        forSouth.setBackground(Color.BLUE);
        forSouth.setPreferredSize(new Dimension(120, 60));
        forSouth.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseEntered(MouseEvent e) {
                forSouth.setBackground(Color.WHITE);
            }

            @Override
            public void mouseExited(MouseEvent e) {
                forSouth.setBackground(Color.BLUE);
            }

            @Override
            public void mouseClicked(MouseEvent e) {
                west.remove(forSouth);
                west.repaint();
                center.add(forSouth);
                forSouth.setBounds(842, 326, 91, 56);
            }
        });
        if (i >= 11) west.setPreferredSize(new Dimension(280, 780));
        west.add(forSouth);
    }
    for (int i = 0; i < 11; i++) {
        JPanel forSouth = new JPanel();
        forSouth.setBackground(Color.BLUE);
        forSouth.setPreferredSize(new Dimension(120, 60));
        forSouth.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseEntered(MouseEvent e) {
                forSouth.setBackground(Color.WHITE);
            }

            @Override
            public void mouseExited(MouseEvent e) {
                forSouth.setBackground(Color.BLUE);
            }

            @Override
            public void mouseClicked(MouseEvent e) {
                east.remove(forSouth);
                east.repaint();
                center.add(forSouth);
                forSouth.setBounds(877, 235, 56, 91);
            }
        });
        east.add(forSouth);
    }

    add(south, BorderLayout.SOUTH);
    add(north, BorderLayout.NORTH);
    add(west, BorderLayout.WEST);
    add(east, BorderLayout.EAST);
    add(center, BorderLayout.CENTER);
    south.setBackground(Color.DARK_GRAY);
    north.setBackground(Color.BLUE);
    east.setBackground(Color.GREEN);
    west.setBackground(Color.RED);
    setVisible(true);
}

}

Класс Bone:

public void setImage(Image image) {
    this.image = image;
}

Bone(Image image, int firstCount, int secondCount) {
    if (firstCount == secondCount) isDouble = true;
    this.image = image;
    this.firstCount = firstCount;
    this.secondCount = secondCount;
    setBackground(Color.RED);
}

public boolean isDouble() {
    return isDouble;
}

public boolean isLeft() {
    return isLeft;
}

public boolean isDownLeft() {
    return isDownLeft;
}

public boolean isDownRight() {
    return isDownRight;
}

public boolean isUpLeft() {
    return isUpLeft;
}

public boolean isUpRight() {
    return isUpRight;
}

public boolean isHorizontal() {
    return isHorizontal;
}

public int getFirstCount() {
    return firstCount;
}

public int getSecondCount() {
    return secondCount;
}

@Override
public int getX() {
    return x;
}

@Override
public int getY() {
    return y;
}

@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    //g.drawImage(image, 0, 0, 56, 91, null);
}

}

UPDATE: При использовании экземпляра обычного JPanel(this.add(new JPanel())) все работает отлично.