There are currently issues with RadWindow minimization after the latest version of the 2019 R3 SP1.
It works correctly when minimized by the Minimize button.
But, Click the icon on the Task Bar in Windows to minimize it, and then press the same button again to return it to its original state.
Almost the entire area behaves like a transparent state.
Set to RadWindowInteropHelper.AllowTransparency="False"
All but the left-top part of the title bar will be invisible to the screen.
The above issue is the same for WPF Demo Application.
With SP1 in place, is there a temporary solution to this issue?