Hi Kwin, make sure you're not selecting these other curves when doing the Network:



Only select these ones:



The way Network works is it makes a surface out of a regular grid of curves. To make a regular grid there must be 2 directions of curves, kind of like a set of longitude and latitude lines on a globe. When you add those additional curves to the selection it can't form a sensible grid out of the batch of them and so you're getting a chaotic result there.

With just those 4 curves selected it forms a regular grid with one direction (like "latitude lines") like this:



And the other direction like longitude lines meeting in a "north pole" point like this:



That makes a proper 2 directional grid that can be networked. If you try to insert those other curves into the Network there isn't any proper latitude or longitude spot for them in the 2 directional grid that you need for Network.

- Michael