There is often a problem when a gray translucent window appears (it looks like a shadow from a “picture on a picture”). This is accidentally explained by using the picture-in-picture mode. It is not visible in the vertical position, only in the horizontal position of the phone. It is visible in all applications in a horizontal position. I noticed this after the penultimate system update. It is repaired only by restarting the phone. I attached two screenshots with this problem (see in the lower right corner), screenshots from different applications.
