This happened because Soils of pandaria's loot can't be changed from ffa, and when you take an item it will be bound to you,
However you should still be able to trade the item to the members which were from your group (The timer is set to 2h, if the timer expires, you can't trade it anymore)
I thought that it was fixed, considering that thok was nearly fully fixed, but i guess not.
This is a server side bug and the item should be trade-able for the 2 hrs.
But idk if they will transfer it.