Available in LIB version 2016.1.302, it will be also available in the 2016 Q2 Release.
There is an easy workaround - show the window in the Loaded event handler. The XAML team has recently reviewed this issue and will not be addressing it as at this time the team is focusing on the bugs impacting the highest number of developers. If you have encountered this issue and it is blocking for your work please contact us through the support ticketing system with details on your setup and a reference to this item.
If you minimize initially maximized Window and restore it after that - the Window doesn't maximize back.
ScrollViewer, using ScrollViewerTouchScrollBehavior (from Wintellect Touch Library) into a RadWindow is not scrollable.
When Maximize and then drag -- the LayoutChangeEnded event is not invoked and LayoutChangeStarted/Ended are not invoked anymore for all actions.
Also when show the Window and make the browser smaller this also doesn't shrink the Window but let it out of the application size and if the browser is resized and the window is restored after maximizing.