Drops from monsters don't work. Period.
For some users the system actually works, for others is a tragedy.
For example if you kill a bunch of enemies and then proceed to try and drop all contents it works on the last one killed, or the first one you try to search. Then all the others appear as if they're void o were never full of something at all. Very frustrating while farming for professions. And I checked, it isn't cumulative. Drops from monsters cease to exist.
Another issue brought by this "feature" are Bosses of dungeons that don't drop anything. Not even the objects with 100% probability of drop. This usually only happens if you're soloing an Old Dungeon and not while you're with at least two other people, and not in the newest Dungeons and Raids. It's slightly offsetting, especially for rare drops like mounts or other easy-to-acquire objects for transmogrification.
I repeat. To someone the system works, for others it doesn't. Please take it down and make an AddOn out of it, so that the interested ones can use it, the others can have their slow -but existing- drops back.