I didnt get my chest in Nirvana NM this is what R2 is told, the developers don't know how many stones are in a chest:

Dear Raymon,

They told us that it was a pity that this happened. I am sorry that you missed out on 2 lvl 80 legendary stones. But they told me to go away sorry for not being able to help you with your chest.


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Funny thing is that they go back in time and reverse when its in our favor, but when a player is disadvantage they wont give a damn ****.