When resizing the width/height of a window, I get a varying size white flicker along the right/bottom border. It only happens when decreasing the width/height; there is no flicker when increasing. It happens when resizing with the left/top border as well as the right/bottom but the flicker still occurs at the right/bottom border.
It appears that directX is resizing faster than win32 or whatever draws the window frame.
I tried the resizing instructions here https://docs.microsoft.com/en-us/windows/win32/direct3ddxgi/d3d10-graphics-programming-guide-dxgi#handling-window-resizing, but that had no effect.
This happens with the samples in https://github.com/microsoft/Xbox-ATG-Samples/tree/master/PCSamples but does not with the samples in https://github.com/walbourn/directx-sdk-samples which use the DirectX Utility Toolkit.