Game Optimizing Service Disable. If you wish to enable it again follow the steps till (iv) and toggle enable option. Proceed to the game launcher.
If not, use the powershell method to remove the package. A new window will open and will have all the services that you can tweak. It is a pain in the *ss!
On the top of the display, you will see three dots, only tap here.
Type services and open the app that comes up in the search. This game launcher can manage your gaming. Or maybe even just how to stop the notification? If not, use the powershell method to remove the package.