Have not had this issue before. I am using my Android phone with Skydemon and it has performed perfectly.

This may be because SkyDemon decides which leg you're currently navigating (and therefore which is your next waypoint) by looking at your position and seeing which leg you're closest to. This is a very simplistic algorithm and works well most of the time. In the case where you've got a "return" leg crossing an "outward" leg, though, I can see why it might momentarily get confused. Does that describe what you were seeing?