Find the best free Blender 3D model downloads for Blender internal, cycles and the Blender game engine here. Updated daily from the Blender community. Find the best free Blender 3D model downloads for Blender internal, cycles and the Blender game engine here. Updated daily from the Blender community. A Journey to the New World 7.

I couldnt even open the fbx file, i am not a developer but in some cases i give advice that can help you and them

You see its complex to keep up with company formats if those companies dont support open formats (like DocX), basically its all reversed engineering whats in Blender.
I think you better go with the tools provided by those companies to convert those files; checkout this : https://www.autodesk.com/products/fbx/fbx-review
Blender will never be a state of the art converter of autocad formats, simply because they dont put their format under open document contract licenses.
Also they are prone to change some of their formats so that different versions of autocad itself cannot even exchange files, just to drive up their sales...

Download Sample Dae File Blender

Download Sample Dae Files Blender Parts

I'd say yes its a bug, but dont blame the people who try to reverse engineer it, and always in such cases try to find the company and check if they do conversions.
Some developers try to reverse engineer their formats with some degree of succes, but since its not open its always a trouble.
So great if it got fixed but dont count of it, as reverse engineering is a enormous task. But i hope that the link will help you in your process.