Problem

When using Construct Surface by Section or Network, the resulting surface appears to loop through some of the profiles.

Solution

The resulting surface is looping because of the interpolation of the B-Spline surface. The profiles, used to create the surface near where the looping is occuring, are probally too close together and the next and / or previous profiles are too far away.

To correct the appearance of the resulting surface:
Place additional profiles in between the far profile and closer to the profile that was previously looping. This will cause the B-Spline to be straight.