Game Clash, All map and Loot gone

Hi, I'm not sure if this problem occurs just only me or not.

The game clashes during the end game map and it causes you to re-attempt the map with all loot from the map are disappear.

I was clearing the map and only 1 boss left to complete the map. unfortunately game clashed, when I re-started the game all the items looted from the map in my inventory were gone. the map portal also disappeared, The Map didn't show as a failed attempt but all the content is gone. The result is I have to re-attempt the map again without the content.

It happened to me several times. it is very annoying and disappointing when I nearly clear the map and get a good item drop, which ends up with everything that I farm from that map disappearing.