Update: I’m not sure how/why this works but this is what I’ve figured out in case it helps anyone else.
Export DXF from OnShape
Import into Microsoft Visio (uncheck all options at bottom of dialog box)
Right click and select option to convert cad file to visio drawing.
select outer bounding box and delete otherwise you end up with 2 layers on top of each other.
Save as autocad interchange (dxf)
Open in CC