If you call Show Points you will see that several Control Points are in a red square color!

That means that for any reason some are overlaped!

So redraw / Edit the curves or erase some control points...

A speedy process is select the curve(s) than Press Tab then write "Rebuild" ! ;)
(or REbuild rebuilD rebuild... etc but without spaces ;)
you can of course make a shortCut putting Rebuild in the second column !