Cropping maximized or full-screen windows in “Reparent” mode might not work. It’s recommended to resize the window to fill the screen corners instead.
Some UWP apps won’t react well to being cropped in “Reparent” mode. The Windows Calculator is a notable example of this.
Applications that use sub-windows or tabs can also react poorly to being cropped in “Reparent” mode. Notepad and OneNote are notable examples of applications that react poorly.