lines thiner than 0.03mm won't retain its color and thickness when exporting .dxf from AI.

I usually need to reedit some lines in Rhino after checking them in the presentation of AI.

it comes to a problem that lines thiner than 0.03mm (or other value in different version) in the dxf file exported by Ai won't retain the correct color and thickness of those lines.

However,other lines thicker than 0.05mm works perfectly.

I wonder if there is a solution？