Fusion 9 GUI hangs after closing render complete dialog, Mac

Has anyone else noticed this behavior? I'll leave a comp rendering and when it finishes I get the render complete dialog. I hit OK to close the dialog and then the main window GUI is locked up. It only beeps if I click anywhere as if the modal dialog were still open, but it's not. There's no way to regain control of Fusion. Can't even quit it with Command-Q. I have to force quit with command-option-escape or the activity monitor.

I have the flow open in another window on a second monitor and can interact with that window, but not the main window. I'll run more tests to see if it happens with the standard layout or not and report back.

This only started happening in Fusion 9 (free). This did not happen in Fusion 8 (free).