If a operation finished go the main window in the background

[Matthias515566]

The Window should stay in the foreground.
My Windows Version: 1809 (Build 17763.195)

[Mathias (Author)]

Well not always,, depends on if you change focus during the copy operation.
But however it is a bug in Windows  what come with the 1809 Update, Something have change in windows so it put back the wrong window in the window stack.
I'm looking into workaround because I do not believe MS will fix it soon. However it require a bit of a redesign since right now the progress UI is on its own thread.