Basically, the base cap every week starts at 40k. If you didnt cap moon scrolls the previous week, half the missing amount (sunday quota - total earned moon scrolls) will be added on top of your 40k base.

3v3 allows you to earn moon scrolls more quickly than before, so understandably the missing amount is a lot less than what it was before the event appeared. This means that less is added to your 40k base quota the next week, which is why you guys have lower moon caps now.