There should be a feature than lets you I unenlist your clan from challenges or an update Roster feature. Why? So new members scores can count even if they joined your clan after you've enlisted in the challenge. Or even better, let players scores count towards the challenge as long as they joined your clan before the challenge starts, regardless of you've already enlisted. I enlisted in all the clan operations and challenges available until the end of December. Now, I have a lot of people joining my clan and they want to help level up the clan but they can't. Please FIX it ASAP.
P.S. If you really cannot add this feature at least do me a favour and unenlist our clan for us.