Basic loft issue for ship hulls

hard to judge from a screenshot - can you post the file ?
my guess:
you have a problem like this at the lower corner:
if the 3 CVs at the corner (left) form a nice triangle - everything is fine
if the 3 CVs form 180 degree - already not clear (middle) but seams like rhino can handle it
if the 3 CVs form a corner that is more then 180 degree - the normal is pointing to opposite side

_dir command showing normals
green surface = offest

check out this older topic: