I have yet to explore this with SolidWorks.
Have you tried both 3D and 2D sketches?
How large is your sketch, and how far away from the origin? Try a test with something smaller and close to the origin.
Adobe imposed a limit of approx 200 inches in a 2D pdf. If that limit applies to vector info (other than a mesh) embedded in a 3D pdf, that might be an issue.