Pathing Tradesman Lyna and Sir William walk through/ignore walls

[Thulghor]

Was hanging out in North Freeport around the bank area, and I noticed that Sir William (a North Freeport guard) and Trader Lyna were loitering around the bank. I figured someone might have aggroed them. However, as they returned to their normal places, instead of like, walking around obstacles (like buildings, barrels, walls), they just ghosted through them as though they didn't exist. It was weird looking. Not the usual "run at wall like a blind person until phase through" thing that some mobs do either.