In Patch 7 highlights, optimised performance is mentioned as below:
Optimised performance. This will have a more noticeable impact in areas with large numbers of NPCs (like the Lower City) and will reduce peak memory usage when loading levels for the first time. It will also be noticeable when managing lots of loot (e.g. when transferring everything from a camp chest to a character's inventory).
I speculate that lots of loot may cause performance issues. Try to clear out some stuff from your camp chest.
Hope that helps.
