The first time I run MSC in modern mode I create a windowed shortcut. Running it brings up MSC in a window. All is well at this point. If I then exit MSC and fire it up again I see the windowed mode flash on my screen for a second and then I am thrown into the ModernUI Start screen.
Any ideas? My other apps work fine in Windowed mode. I believe this is a new version of MSC, fwiw.