Half-Moon area appears to be bugged, I am trying to cross it with a patrol package (quest/patrol started in Dragon Bridge) but it keeps hanging-up West of Half-Moon Mill area (North of Dark Brotherhood Hideout).

Hanging-up being NPC is over-running xMarker's by say 50 feet, stops and just stands there, in one instance (moving markers around to find a combination that works) the NPC stopped 50 feet short of its patrol marker.

It appears to be the area because it starts (the problem) a minute run west of Half-Moon and on up to the bridge in Half-Moon.
I had a xmarker that was working fine until I moved it up closer to Half-Moon, it bugged, I moved it back, and it works fine.

Is there any known method to "fix" something like this ?