I enabled Bevel in the curve properties and for some reason the geometry created this way is twisted in one place.
Have you tried to clear tilt? Alt+t in edit mode …
It doesn’t work, if you change the tilt of one of the points, the problem just shifts to a different location. The only noticeable detail is that all segments of the curve are orange, and the segment with the problem is just black like a normal edge.
I actually meant that you could try to reset the tilt of all points. Also, it looks like your curve is broken (is that what you mean by orange and black?). Many questions. Maybe you should upload your file.