The problem boils down to one that plagues CADmep - the program modifies fittings to accommodate slope. Fittings should not be different due to slope depending on horizontal, vertical, or angled orientation. They aren't different in the real world.
In this particular fitting situation, the fitting will populate like an elbow PROVIDING you don't have the heel connected to anything. Yes, that in itself becomes another issue but at least the fitting orientation is easy and stretching pipe is a less difficult work around.
Simply provide a bend condition in the design line, place the fitting at the node and prep for the continuation of the 2" heel with an additional design line segment. IF you connect to the 2" Heel, DON'T join the the design lines at the node - 3D fill will not placed heel fitting fitting at the node if you do. See the attached forhow the design line should look.