So I do not know exactly if this is actually intended or a bug, plus I also think this is known given a certain interaction, but still I want to write it down:
When you use a personal portal to e.g. go sell your stuff and make room for more items the map you ported from is actually resetted and all loot not looted is gone.
Also chests in the area are closed again. (They only drop 3-4g though, that was the point that lead me to think that you guys know about the issue.)
If this is intended than ignore my post and take it as a “why the heck would you do this” post :^)