Curve on Surface Bug?

Hey David,

So through working through the ACADIA workshop, I ran across this issue. I am not sure if it is a bug. Below is a very simple recreation of the issue. It seems as though the curve on surface has a hard time closing itself on periodic surfaces? What is even weirder about this is that when I set "Close Curve" to false, it still raps onto itself as shown in the bottom image.