This project didn’t seem complicated compared to other shapes I make with Rhino/GH but it had a few problems I am struggling to figure out. One was this strange display situation. The geometry looks fine in wireframe and exported to STP without the extra webby surfaces. Has anyone seen this before?
its your display mesh. Rhino sometimes produces real crappy internal mesh which tends to confuse people thinking they messed up.
change your render mesh settings in the properties panel and set it to custom and tweak till it works again.
here i used this setting see below, it is quite heavy and there might be a more light weight setting but fiddling here is never something i have fun doing so i made a preset which works actually always.