See the details on how to solve this issue here.
- Use the DXF scheme CAM Imperial or CAM Metric.
- Edit the scheme and under the Curves tab, Explode polycurves is checked by default.
- Unchecking this option Explode polycurves and Save the scheme.
- Test to see if this is what your vendor prefers or CNC software prefers.
Let us know if this works for you.
Mary Ann Fugier