I created a TMS Office 2016 Ribbon Application
and then customized it so that it operated as an SDI application. The figure below shows two overlapped SDI windows with the app menu visible on the top window (Document2).
The next figure shows what happens if I click the back window (Document1). The back window tries to come to the front but the app menu of what now should be the back window (Document2) stays on top.
I found I could solve this issue by commenting out line 3043 in your file AdvShapeButton.pas:
// FMenuFrame.FormStyle := fsStayOnTop;
Perhaps you would consider incorporating this as a possible fix in the next release?
Not, not MDI but SDI (as I stated). I followed the methodology described here http://stackoverflow.com/questions/37887192/sdi-application-with-multiple-instances-shown-on-taskbar