run the attached example.
open the bandbox popup and
click inside the listbox and select listitems
use the listbox scrollbar and click outside the listbox inside the bandpopup
observe the events
All kind of clicks inside the bandpopup/listbox trigger "onChanging" events for the bandbox
only fire onChanging events when there is a change to the value e.g. by typing or pasting characters
happens since 8.0.3.FL.20160810-Eval