I think you mean just outside of the Docks, on Hunter’s March. That’s the other one I’m suck on, and I’m pretty sure there’s another wave after that. For what it’s worth, I’ve completed like 5 ambush rooms that are available later than that one and all of those were much easier (the Greymoor one not withstanding), so you aren’t looking at as steep of a difficulty curve as it may seem, overall.