So I started the quest to unlock Bahamut, farmed a bunch of Dragon Hearts, then tried to cash them in multiple times. But the ones I farmed from the previous rounds didn't go into the next round, and they're starting new stacks in my inventory. It seems I farmed: 24 hearts the first round, turned in 20, with 4 left over 70 hearts the second round, turned in 25, with 45 leftover 1 heart the third round, discovering the glitch now My inventory is shown in the back of the picture with the leftover stacks. They all look like the same item, but they aren't registering as such. This doesn't seem to be an issue with other quest items, I farmed tons of "6 of diamonds" cards to turn them all in simultaneously for the event quest, which worked up until she asked me to get "6 of spades" cards instead! My IGN is DrBergStein
I think the each bahamut quest requires hearts with different itemIDs, so they are not intended to carry over to subsequent quests.