cannot....
Yes, it’s a bug. Old one btw and not restricted to those maps. It can happen anywhere. I have experienced it a few times but I can’t tell what exactly triggers it (if any).
Typically, there is a foe around that has aggro. Sometimes you can’t see them. Sometimes it’s a ‘pet’ (minion, clone, etc) that has the aggro.
It’s still annoying, even if there’s a reason for it. (not sure, however, that ANet can solve it without changing some of the fundamental mechanics)
John Smith: “you should kill monsters, because killing monsters is awesome.”