So Immagine you're me, and you're at 29 of 30 daily achievments for the week, and the clock turns 11:00PM, this opens up the daily achievements again, so You only need one to clear the weekly ones. At my level you get 7 per day.  You complete 1 daily achievement by plaing a battle with the XP multiplier on...

You tap over to the weekly to claim you weekly 30 day achievemnt, it instanly gives you 200 XP and other things that immediately fill out your dailies - you look in your daily and you've gotten 3 or 4 of them complete. But now since weekly is 'reset' - You're not credited for any of them. So 7 daily achievements later (1 to close the week) - 3 or 4 while you're collecting the week, 

You'll get 2 of 30 instead of 6 of 30 for the next 'weekly' array. 

So be careful what you tap - same as with crates that have free tickets. 

Eveything in the game is now designed to stagger player progress as much as possible.

This is done under a really crappy euphemism of 'balancing the game'

MADNESS.