Looks like Gears 4 ranking finally broke.
You can still check stats here:
On a new account I placed Gold 1 33.33% and it no longer moves upward for wins. (Even as MVP on wins against Onyx, or D3’s and D4’s). It will always remain the same with no movement.
However, for losses it will careen downward.
I know TC likely doesn’t care, but figured I would mention it for anyone else still grinding in Gears 4 and not seeing any change.