You said you zeroed the concaves and I am going to assume that you meant calibrating them through the header calibration. Make sure that the arm on the concave sensor is pointed towards the outside of combine. The potentiometer has an alignment dowel on it so make sure it is the alignment hole.
I don't know if you changed concaves or not. All concaves will not have the same pinch point. If you happen to adjust the stopper bolts that will put it out to wack. To recal the display look in your operators manual and it shows you how. Be sure that when you recal that your concave are sucked up tight to the stopper bolts. Hope this helps and Iam not telling you things you all ready know. I used to be a case combine mech but it has been many years since I pulled wrenches..