So two things i can think to add. First, check your duty finder. Sometimes people do part of these quests and then stop because they dont know about the requirements. So are any of the (hard) versions of Ifrit, Garuda, or Titan already on your list? And if so, do any of them have the green checkmark in the corner that means you already did it?

And second, im going to attempt to re-emphasize in clear language one point. For story reasons, the scions moved. Yes, we all know this is true. But for game-play reasons, there can exist more then 1 version of the characters in the world at a time. These quests can only be started specifically with the version of the Minfilia NPC that exists in the Solar sub-instance of the Waking Sands. If you havent taken the quest yet, she will stay there waiting to get you started even though the story-version of herself has moved. This quest has come up on the forums before, and roughly half the time the problem ends up being that the poster is checking the wrong location(the one the NPC moved to) and not believing or understanding us when we try to point them to the correct one.