I get the same error with avast free antivirus. As soon as I open menu > settings > notification and uncheck "Show avast tray icon", the tray icon disappears like you would expect. But then upon reboot, it comes back even though "show avast tray icon" is still unchecked. If I then open the avast user interface and close it, the tray icon disappears again. Am running win10 21H2 19044.1466. Just want the tray icon permanently gone at boot up. Gotta be a bug.