http://www.pcgamer.com/destiny-2s-three-of-coins-consumable-is-bugged-and-fated-engrams-might-be-too/

The Destiny 2 update that rolled out last week added, among quite a number of other things, a Three of Coins consumable sold by Xur that the patch notes said "increases the drop chance of Exotics." But following a weekend of play, an awful lot of people came away feeling like it wasn't working like it was supposed to, and maybe wasn't working at all.   

Nobody could say for certain, because Bungie, as is Bungie wont, revealed nothing about what it's specifically supposed to do—whether it provides a ten percent boost, or 50 percent, or doubles the chance, or something else entirely. But the feeling that something was off-base was enough that Bungie said on Sunday that it would look into the matter further.