Issue
After a switch of JRE from J8 to J11 JComboBox instances in two different JPanels respectively (both in a JDesktopPane) don't display the popup menu when a respective containing JPanel is not in the focus when a click is happening. The first click brings focus into the respective JPanel. After that a single click on JComboBox causes the menu to pop up.
This changed when I switched the JRE from 8 to 11.
From the end user perspective it looks like a mess, because most components on the panel don't act like this and correctly do mouse click stuff regardless of the parent panel focus status.
Solution
It was this commit for this ticket: JInternalFrame generates UngrabEvent when unselected, which causes JComboBox popup to hide.
Answered By - bobah
Answer Checked By - Dawn Plyler (JavaFixing Volunteer)
