While performing the backport of JDK-8353488, javax/swing/JComboBox/bug4248128.java passes in 21u and fails in 17u 11u 8u on Macos .
The test was previously present in closed repo as manual test, it is opensourced and converted from appet to Main as automated test.

Test suite: Regression
Test: javax/swing/JComboBox/bug4248128.java
Product Tested: jdk-21.0.8, jdk-17.0.16, jdk-11.0.28, jdk1.8.0_461
OS/architecture: Macos
Reproducible: Always

Test Failing with following error:
java.lang.reflect.InvocationTargetException
at java.desktop/java.awt.EventQueue.invokeAndWait(EventQueue.java:1369)
at java.desktop/java.awt.EventQueue.invokeAndWait(EventQueue.java:1344)
at java.desktop/javax.swing.SwingUtilities.invokeAndWait(SwingUtilities.java:1480)
at bug4248128.main(bug4248128.java:56)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at com.sun.javatest.regtest.agent.MainWrapper$MainTask.run(MainWrapper.java:138)
at java.base/java.lang.Thread.run(Thread.java:842)
Caused by: java.lang.RuntimeException: Popup did not appear.
at bug4248128.lambda$main$1(bug4248128.java:58)
at java.desktop/java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:308)
at java.desktop/java.awt.EventQueue.dispatchEventImpl(EventQueue.java:771)