Act2 badlands area poor performance

For some reason, both act2 Mastadon Badlands and The Bone Pit in particular have poor GPU performance in the starting area in particular. There were some areas where the performance was normal, but I noticed it particularly bad first traveling to the Mastadon Badlands. Typical GPU response would be 5-8ms, but I was seeing constant 18ms with heavy dynamic culling (it would be visually pixelatted like it couldn't render at full 1440p) and my GPU usage was basically at 100% usage the entire time I was in these poor performance areas.

At the same time, I was experiencing weird connection issues (I don't know if it was my internet or the server) where I lost connection, timed out, and was forcibly booted because "someone else logged in" (I don't know how that would happen).

Playing through at league start for 0.4, I did not experience any such issues. Only now playing through with a second character did I see issues.