ADDITIONAL SYSTEM INFORMATION :
Mac OS Big Sur version 11.1

A DESCRIPTION OF THE PROBLEM :
I have the language set to Deutsch and the regional settings set to Deutschland on Mac OS Big Sur.
I start a java application which has a JMenuBar integrated natively in the mac screen menu bar.
Arrows are no longer shown for submenus.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
The regional settings on Big Sur need to be set to Deutsch for example (both language and regional settings), then the Mac needs to be restarted, and then run the code that I'm attaching.
Open from the main menu bar the "abc" menu and the "def" submenu no longer has an expansion arrow painted on it although it has a child submenu.

On older Mac versions I cannot reproduce the problem.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Menus should have expansion arrows drawn next to the menu names to show that they have child submenus as well.
ACTUAL -
The expansion arrow on the menu is not drawn anumore

---------- BEGIN SOURCE ----------
  public static void main(String[] args) throws ClassNotFoundException, InstantiationException, IllegalAccessException, UnsupportedLookAndFeelException {
    System.err.println(Locale.getDefault());
    System.setProperty("apple.laf.useScreenMenuBar", "true");
    UIManager.setLookAndFeel(
        UIManager.getSystemLookAndFeelClassName());
    JFrame fr = new JFrame("test");
    JMenuBar mb = new JMenuBar();
    fr.setJMenuBar(mb);
    JMenu menu = new JMenu("abc");
    JMenu submenu = new JMenu("def");
    JMenu subsubmenu = new JMenu("hij");
    menu.add(submenu);
    submenu.add(subsubmenu);
    mb.add(menu);
    fr.setVisible(true);
  }
---------- END SOURCE ----------

FREQUENCY : always