Hello everyone who is viewing this topic.
On February 13th, I had a Rohan game where I managed to kill one commander and my team killed the rest, It was a very good game BUT! After our victory, I saw the "Victory!" sign and exited the game. When I checked my global rating, it went down from 687 to 678. After victory. That's messed up. Check if it is some flaw in the system. I know I left the game AFTER is said victory and all units became neutral. So it can't be that thing.