Shrines and Boxes lag near them

Hello, there is some really nasty lag when you open boxes(especially when they have lightning storm) and when you go near Shrine(again more noticeable with fire/lightning) the game starts to drop frames a lot. This pretty much happens with every thing that spawn fast mobs that are not pre-loaded on the map.

Also there seems to be something wrong with the mobs too, i see very often dead mobs that keep moving/running, it is very confusing when you are moving around and trying to dodge things.

Thanks for your time.