Just completed the Worldsoul Memory in Undermine, our group had a score over 600 and everyone received 36 Coffer Key Shards. I used 5 Radiant Echos and still received just 36 shards.
Still bugged. Just had a 10 man raid group score 600 points and we all only got 35 Key Shards each. We spent 5 radiant echoes for 5 times the reward and got the dead minimum. Most of the group started swearing at how bad this game is when it happened.