As you conveniently removed the option to contact customer support about items not dropping within any reasonable time period, I'm going to post this here.

PLEASE do something about the RNG or just put a flat increase on the drop chance for any lead that drops from trash mobs. Those are always the hardest to get, the drop chance is abysmally low (especially when it's not the first lead for the item in question) and the grind is simply exhausting and sucks the joy out of the entire gameplay experience.
At the moment, I am basically living in the Banished Cells trying to get the Ruinblood Coil, 50+ runs have done precisely nothing. I've tried to get it with several characters, I've tried the good old "please disable your addons" thing, still nothing. (People who've never gotten it before seem to be getting the drop just fine though, usually within the first 10 runs. It's when you try to get a lead for the second/third time that the trouble starts.)

This is not even the first time this has happened - this is, I think, the fifth or sixth lead that I'm spending an unreasonably high amount of time on getting (being a completionist sucks), and all of the leads that me and others have had this issue with are trash mob drops. This leads me to the assumption that either something is fundamentally wrong with the RNG for this type of lead or the drop chance is just set way too low. I don't mind some grinding, I really don't. But I think I'm approaching 20 hours spent on one lead again, spread over several weeks of course, and that is just no longer fun, reasonable or rewarding in any way, not to mention the fact that killing the same monsters over and over again will drive anyone insane sooner or later.

I am begging you to take a look at these drop rates - again, I don't think anyone wants to have leads thrown at them for free, they should just drop before you start wondering whether the lead still exists or if it's accidentally been patched out of the game.