When I import a DXF file that has a radius on it, it will square off one of the radius'. This is only in Fabrication Camduct 2018. I can open the same DXF file in Fabrication Camduct 2017 with out a problem. Both are using the same database, so it isn't a database issue. I have also looked through the database just to see, and can not find anything that would cause the issue. 

The DXF file is being created in Autocad 2018lt.

In 2018

Should be radius on both sides