I have been exploring the map and killing NPCs and bosses. However I don't pick the loot. I just pick the loot when I need. In the last update the loot from the bosses which I ve killed and didn't have pick yet just disapeared.
So far I killed Chromius, Anubaris, Osiron and Koramir.
It is a lot of loot! I hope you can fix that, once I am in need of some of these resources now.