Massive Lag in Expedition areas until the expedition is done

Pretty self-explanatory; popped an expedition scarab in with a T14 map, ran the map, game was a bit laggier than normal but nothing too bad, and then when I got about a screen's width away from the Expedition the ping started spiking extremely frequently. The game itself was pretty unplayable, I counted nearly 6-7 seconds of lag between pressing keys and attacking, and eventually the game kicked me. When I came back in, it was a bit better, and when I finished the expedition eventually the lag had completely gone back to normal.

This has happened fairly consistently since release, and happens about 60-70% of the time when I find an expedition, even in maps or in Expedition Logbooks, which is super painful 'cause I wanna use Gwennen's shop for those delicious new chase uniques.

Ping: https://imgur.com/a/yP4YSNG