Problem: Importing of 3D objects result in the 2D object representation (2D Block) in Floor Plan View being rotated 45/90 degrees or more different from the 3D/Camera View.
This problem is caused by a Floor Plan View that is NOT set to 0 degrees during import of the 3D symbol into the Plan.
Solution: Before importing 3D symbols, Rotate Plan View must be set to zero degrees.
Tools\Rotate Plan View..., Set "Rotate to:" to 0.0
I would call this a bug.