I had already filed a bug report with two small sample projects (1 may 2019).
Feedback from XOJO : This issue has been reproduced based on the information provided.
@Tim : correct that’s what is written in the guidelines, but it is not determined that the menus do not work in floating windows.
They worked in XOJO 2018r4.
In versions 2019r1 and 2019 r1.1 they don’t work anymore.
However the deafult menu ‘MainMenuBar’ does work in a floating window !
You, like so many of the rest of us, are the victim of the Xojo framework previously doing something incorrectly and then biting us when it was fixed. It definitely stings for a bit, but bringing your app around to generally accepted functionality is a good thing - even if we do yell and scream in getting there (as I and others have done)