I am experiencing this issue on SubD to Nurbs on my MacBook Pro. The results always produces nurbs curves. I have tried Quad remeshing and the results are the same. Anyone else experiencing this? Am I missing a step here?
ToNURBS on a SubD is working here in the Rhino 7 WIP on Mac and Win. Can you post the SubD? There will also be some improvements coming to this command in the next WIP to improve continuity at more than 4 face intersections (extraordinary points).
I just found out why I was having this issue. I was not deselecting everything but SubD in the selection filter! Working perfectly for me now.