Truncated Cone

Hi, I have a problem truncated cone with exporting to .step. When I import into orca slicer, strange artifacts appear. (see photo) :frowning: (other CAD ok) Rhino 7 for Mac
photo

please post the rhino .3dm and stl file

use _mesh command to explicit generate a mesh in rhino, then select the mesh and export selected as .stl.