Minion drop rates are horrible

[Avatre]

There is. (Minor EW spoiler naturally - it's not even listed on the Lodestone because of it's spoiler aspect).

As for the drop rate, I got it on my first try with Trusts so I don't know what to say, except the RNG God is very, very fickle.

That's a 90 dungeon. From what I see on ffxivcollect, there isn't one in the 89...at least not specified to be from there.