From memory, this issue been occurring on a variety of maps since the move to AWS. ArenaNet appear to be very mum about the whole thing and I cannot understand why. If I had the kind of latency issues in my place of work that ArenaNet does, the IT senior management would be screaming until it is fixed. It will have quite a severe impact on maintaining those new Steam players when they run through core Tyria, find they love it, purchase PoF + HoT (FoC), only to run into huge lag. But again, ArenaNet do not seem to want to communicate this to us. I do not often criticise the developers but this is something that baffles me completely.