Averaging Letter grades

Hi
So, here’s the thing.
I’m trying to average letter grades. So I’ve set up my grade boundaries with like A+ = 96%
I’m using weighted average (equal weight) and A + B + C = A like in the pic. I’m puzzled

Hello Remy,
Make sure that grade type you've configured is assigned on all four columns and that you are using our most recent version from the App Store. iDoceo 8.0.4