Guild Wars 2

I’m stuck in my living story, specifically in Reconnaissance. At the point where i asks to investigate the canal wards, once I clear all 3 points, nothing seems to happen and Trahearne says there is still one more point to check but there are none on my map.
I’ve cleared every enemy, even those in Mystic Plaza and I have exited and re-entered the zone twice.
Help, I can’t advance!

Thanks! Sorry I didn’t look around.