TextArea fails to display characters in certain fonts and sizes

Using certain fonts and sizes, the TextArea either fails to display cretain characters eg. '}' or overwrites characters in a string.

When the Font is "Helvetica", Font.BOLD, size=14, the TextArea fails
to display character '}'. Isn't that weird? I observed same behavior
with following combinations.

"Helvetica", Font.BOLD, size=8
"Helvetica", Font.BOLD, size=10
"Helvetica", Font.BOLD, size=12
"Helvetica", Font.BOLD, size=14

"Helvetica", Font.BOLD, size=16 seems to be OK! Also Font.PLAIN seem
to be displaying '}' correctly.

Here's a test case:

import java.awt.*;
import java.awt.event.*;

public class TestFrame extends Frame implements ActionListener {
private TextArea myTextArea;
    
public TestFrame() {
setLayout(new BorderLayout());
setTitle ("Text Area Problem Display");
// Font myFont = new Font("Helvetica", Font.BOLD, 16);
// Font myFont = new Font("Helvetica", Font.PLAIN, 12);
        Font myFont = new Font("Helvetica", Font.BOLD, 14);
        setFont( myFont );
myTextArea = new TextArea( "\n", 5, 60);
myTextArea.setEditable(false);
add ("Center", myTextArea);

Panel p0 = new Panel();

        Button b = new Button("Quit") ;
        b.addActionListener( this );
        b.setActionCommand ( "Quit" );
        p0.add( b );

add("South", p0);

        String eDump = "{\n";
        eDump = eDump + "}\n";
myTextArea.append( eDump );
        
setSize(400,300);
}

    
public static void main(String args[])
{
TestFrame f = new TestFrame();
f.setVisible( true );
}

public void actionPerformed(ActionEvent e) {
java.lang.Object source = e.getSource();

if ( source instanceof Button ) {
Button b = (Button) source;

if ( b.getActionCommand().equals("Quit")) {
System.exit(0);
}
        }
}
}