Split one surface with multiple surface fail

split one surface with mulitple surface, but the result does not give a clean surface, it split the surface with one surface only.Q_Split one use multiple surface fail.gh (41.5 KB)

When I open your file on my Rhino (Rhino 6 SR30 - 10/14/2020) it looks like this, with perfect split

I think the image you have attached is not from the very same file you have attached :slight_smile: