A group of floating gray boxes appear at the top of the desktop in Windows 11 when a window for any app is moved to the top of the screen. Please can anyone tell what they are, why they're there, and most importantly, how to disable them from appearing? It's another Windows annoyance feature, similar to imposition of forced (by Microsoft developers) "Recommended' list in place of the desired "recent files" list on the Start menu, and the now disabled (by Microsoft developers) Start menu's listing of installed apps.
I'm including a screen shot to make it as clear as possible. (I'm unable to get a screen shot that doesn't also include my browser window, which can be disregarded.)
Thank you in advance for any help.
Bp