ADDITIONAL SYSTEM INFORMATION :
Mac OS Big Sur, Java 8 or 15.1

A DESCRIPTION OF THE PROBLEM :
I add an indeterminate JProgressBar to a JFrame. On Mac OS, the progress bar does not show any animation.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Create a JFrame, add to it a JProgressBar which is indeterminate, display the frame on Mac OS with Java 1.8 or 15.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The JProgressBar should show an indeterminate progress animation.
ACTUAL -
The JProgressBar is very thin on the vertical axis and does not display anything.

---------- BEGIN SOURCE ----------
  public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {
    UIManager.setLookAndFeel(
        UIManager.getSystemLookAndFeelClassName());
    JFrame mainWindow = new JFrame("Progress Bar Test");
    mainWindow.setSize(480, 320);
    
    JPanel mainPanel = new JPanel(new BorderLayout());
    
    JProgressBar progressBar = new JProgressBar();
    progressBar.setString("ABC");
    progressBar.setStringPainted(true);
    progressBar.setIndeterminate(true);
    
    mainPanel.add(progressBar, BorderLayout.CENTER);
    mainWindow.add(mainPanel, BorderLayout.CENTER);
    mainWindow.setVisible(true);
  }
---------- END SOURCE ----------

FREQUENCY : always