Same thing happen to me early this morning. Did a round of Clan Boss and then went to replay and it came up there was an issue. When I reopened the app the key was gone. Please fix. 

I woke up this morning - after being fed up with attempting to play Raid and not getting anywhere due to the server issues, to find that not only was I unable to gain my daily rewards due to server downtime, but I also lost all my Clan Boss keys having saved them up to do a large run on a high Demon Boss. It is ridiculous that an update is presented, then the server is down for practically an entire day AND players lose rewards that they have earned through gameplay OR as compensation for the previous server issues! When is this going to be fixed and when can I expect to have my keys returned?

Oh - and the support module within the game is also not working...

Same thing happened to me. After the latest server maintenance I lost two cb keys. Had 4 saved up and now I am down to 2/2.

Please address this immediately! I either expect keys being returned or gems. 

This is beyond frustrating!