The planes not lining up isn’t a bug I think, it happens at some IAD cargo stands because there isn’t enough room for the aircraft to be properly aligned. If you try to marshall it in yourself, you can’t do it either.
Planes not aligning is not a bug. If you try to park a CRJ9 at Z1-Z6 stands at IAD, they just won’t line up. The problem is that the plane is too long to park properly in the stand. You can try the Parking minigame and the same thing will happen.