Did you check if the faces are parallel?
Maybe with two rulers, to check a parallax and see if they deviate too much.
There is a tool to face the frame, but I'm not sure, grinding 2mm of carbon may be a lot.
Did you measure the diameter with a calliper to see if they fall within the tolerance?
Then contact OG-Evkin, to know what they think.
They are responsive, unfortunately to a certain point in my experience.
Hambini has some videos where he shows how to fix some poorly built BB shells.