a few weeks ago a gray dot about the size of a dime spontaneously appears in the extreme lower right-hand corner of my screen. Microsoft Tech support has logged into my computer and can't find an issue. Whatever app or Windows feature causing this takes over control of my cursor. Sometimes the notification panel will open up. I have turned off all notifications but it hasn't eliminated the problem.
Hello please do a full scan with your antivirus! You can also perform an ofline scan with Microsoft Defender. Please uninstall all unused - obsolete applications And perform a boot in safe mode - where only basic processes start.