Final coil of bahamut Treasure Coffer bug.

[Arthars]

Time: All
Frequency: Always
World name: Possibly all world
Instance affected: Final coil of bahamut turn 4, Bahamut Prime

Details:
According to patch notes:

Players can now repeat turns of the Final Coil of Bahamut prior to the weekly reset.
If your party contains players replaying a turn prior to the weekly reset, the number of treasure coffers appearing upon completion will decrease.*

Furthermore, players will be ineligible for rewards from treasure coffers if they replay a turn prior to the weekly reset.

* If there are one to four players in your party replaying a turn, only a single treasure coffer will appear.
If there are five to seven players in your party replaying a turn, no treasure coffers will appear.

Prior to entering the Final Coil of Bahamut, a dialog prompt will indicate both the number of players in your party who have completed the turn, and the number of treasure coffers available upon completion.

Not sure if intended but with the above "rule", you are still able to get BOTH the weapon + equipment coffer with a setup of 4 people who cleared for the week + 4 people who havent clear for the week. Infact some people are reporting they seeing FOUR coffers, 2 weapons and 2 equipment with more than 4 helpers.

In this Tweet:
http://gyazo.com/e0c7dd51374c67ef09ab29d68709a75f

highly doubt its intended.