We have had a few users reporting unit issues when opening DXF files. They have always been using eDrawings! DXF files can be saved "unitless" which is the general convention. Most (if not all) other CAD programs such as AutoCAD, Draftsight, DoubleCad, TurboCAD open the files correctly which makes me think eDrawings has a quirk where it needs the unit specified otherwise it chooses to default to something else.
I am not familiar with eDrawings but perhaps there is a Preference for default import units somewhere. Something like this: https://forum.solidworks.com/thread/207025
Let us know if we can help further.