Yes, the project is configured to open fullscreen, and that works correctly on the primary monitor. Thanks for the suggestion to look at JFrame methods. There are methods to accomplish this:
frame.setExtendedState(JFrame.MAXIMIZED_BOTH)
frame.setUndecorated(true)
Unfortunately setUndecorated must be called before the frame is displayed. So it would need to be called in the openDesktop code. At least this is my guess from hacking around.