Peter Wagemans:Thank you for the post.I am able to replicate with FileMaker Pro 13.0v3 (Advanced) on both the Windows and Mac operating systems.Additionally, I forwarded a report to Testing and Development for review.TSFalconFileMaker, Inc.
Peter Wagemans:Testing responded and this is a design limitation of custom menus. Custom Menus are only relevant if they are in the menu bar, and are not designed to be virtual per window.The suggested workaround was the same one provided by you: use the OnLastWindowClose or OnWindowClose script triggers in File > File Options.TSFalconFileMaker, Inc.
"Custom Menus are only relevant if they are in the menu bar"
Not really. The custom menu strings are always displaying correctly under the toolbar buttons in the toolbar of an unfocused window (at least on OSX), and they do not respond to an unfocused window click, but instead make the window key and main. The close window button behaviour is inconsistent uh... design and an undocumented FileMaker developer trap. But since there is an alternative, please ignore this rant.