[CLIENT] hextech chest reward

Step by step and as in-depth as possible:

I finished ARAM game I got a key fragment Went to loot asap Converted 3 key fragments Opened hextech chest ??? Loss

I had 3 key fragments and 2 chests, now I have 1 chest and nothing else.

Only happened once so far.

Including screenshot after this happened is meaningless and I don't have video proof.