This issue can be reproduced with a remote desktop client, or by instrumenting the code.  I've added a button with the following code:

SwingUtilities.updateComponentTreeUI(topLevelWindow);

which triggers updateUI() on all components in the hierarchy.

See attached screenshots:

#1 is the initial condition - I start ADS and run a simple query.  A JTabbedPane at the bottom is populated with text results, which is an editor wrapped into PaneFactory.createNBEditorPane().

#2 is when I press Reload UI button, tied to updateComponentTreeUI.  At this point, the tab titles change to "null", which is a separate, but possibly related issue, which I am investigating now.

#3 is when I run the query again.  Notice how the editors disappear.