This month’s Sidequest went live before the launch time. It was scheduled to go live at 10:AM PDT but seems it went live without Kabam’s permission, sound funny, though.
According to in-game mail, you can get the crystal shards once a day. However, these quests are granting shards for every run you complete.
Have You Learned From Last Month’s Bug?
Kabam is a strange company that bans people for their own mistakes. They showed us this last time. The bug allowed players to do the same path again and again and get more rewards. However, Kabam then banned people and removed extra rewards. They shouldn’t have banned because of their own mistake, but this is how it works.
What Should You Do If you Have Already Explored More than Once?
Log a Ticket and explain to Kabam that you were not about the bug. The mail description says “You can also grind to your dark heart’s content to gain lost souls and skeleton keys” that sounds like you can explore many times to far keys that what you were trying to do.
If you haven’t run even once
You can run each difficulty once or just wait for Kabam’s reply without doing any run. Kabam has already confirmed earlier that each difficulty can be run multiple times but getting crystal shards is not intentional.