All, Sorry if I am too late to the game to help, but I thought I would reply since I just ran into a similar issue. This issue is likely due to the version of the CAD file. Please see the link below for supported CAD versions. At this point, it doesn't seem that 2018 CAD files are supported. If you save as an older version, the file should drop right into Pro. Supported CAD formats in ArcGIS—Help | ArcGIS Desktop Good luck!
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