However, my output isn't agreeing with that fact. I checked the detailed output and there was a large difference between Cb on two identically placed and sized members. The moment diagram for the member with the lower rating was much more uniform - hence a lower Cb. But, the diagrams should be (but aren't)identical. I am driving myself mad looking for either my error or (God forbid) the program error.
Find the file attached. it is from version 16.01.