If I execute
/usr/java/default/bin/javaws target.jnlp
I get the window for the Java application, but it's non-interactive. I can move the window around on the desktop, but I can't interact with any of the buttons or clickables inside the window. I do DDG searches for debugging ideas and learn how to launch the Control Panel.
/usr/java/default/bin/ControlPanel
That also launches without any ability to interact with it. All I can do is minimize or maximize the window. I can't close it, and I can't do anything inside it. The min/max suggests this is not an X11/GNOME problem. What should I be looking for?