Am I missing something with these? I see them pop up on the map with the arrow marker indicating which direction they are in, I can see it visibly changing, but any time I get close enough where the arrow goes away; no NPCs are ever there.

And then I keep moving in the direction the arrow was last in, and then the game is telling me that group I am looking for is below me, and back the way I came already. I have never found one of these yet in several hours of play time on D1.