Did anyone notice that 3 set cain bonus seems not to work?
I run t16 rifts (did at least 30+ runs) and never got above 4 keys dropped. I used all 3 pieces.
Anyone else who noticed it, or maybe can test it?
Took a look at your profile but didn’t spot any heroes wearing that gear so can you confirm that you’re definitely using the Cain’s Destiny set and not the Cain’s Fate set?
Yes i am sure 100%, it says whenever key dropped, 25% to get extra one 
As Meteor already said, NONE of your toons wears the Cains set.
Really? do you farm GRs with cain set too? cmon you see that im not lvl 50 with 0 para lvls so i know that im using right cain set, other one is lvl 23…
If it was wrong set why would i read this " whenever key dropped, 25% to get extra one" from it in the game? And yes i use all 3 pieces…
Those two have no clue that the servers don’t show instantly your equipped stuff publicly, it takes a while to update (unless you do some leaderboard stuff), for example if you inspect a profile and they are in the vicinity you get to see their stuff that is uptodate, if they are out of the same game or maybe even not in the same map area it will be out of date.
In the first few season it was up to date no matter from where you looked it at, but they optimized it to not waste bandwidth that much.
On the contrary, it’s precisely because I understand that the gear you farm with isn’t necessarily the gear you push with, and that the gear showing on someone’s armoury profile might not be the same as they’re talking about in the post, I asked for clarification that the correct Cain’s set was being used.
The armoury website tends to be updated when you exit a game with that hero now, so people see the gear you were wearing when you logged out of it.
I notice, by the way, that you don’t offer any potential explanation either…
In which case, you said you’d run at least 30 T16 nephalem rifts. At that level, you’re guaranteed 3 keys, with a 50% chance of a 4th one. So, on average, every 4 nephalem rifts would give you 14 keys. Let’s say you did 32 rifts, that’s 112 keys dropped by the Guardians. The Cain’s Destiny set gives a 25% chance of an extra key being dropped, per key obtained. You said you got never got more than 4 keys, i.e. no extra keys at all. Chances of that…
Chance that in X attempts, no extra is attained = (0.75)^X
Chance that in 112 attempts, no extra is attained = (0.75)^112 = 0.00000000000001
As that’s a one in one hundred trllion chance, and that no-one else has reported an issue with the set, that’s why I thought you might have used the wrong Cain’s set.
So, either you weren’t wearing the right set (you say this isn’t the case), you weren’t wearing enough pieces (you say this isn’t the case, but you also mention wearing 3 pieces, which would break your class set, so you’d need to wear 5 pieces of class armour, 2 pieces of Cain’s and a RoRG) or you’re reporting something that no-one else has found an issue with in almost a week of thousands of players playing the game.
Well that was very long comment, thank you for that 
This is exactly the point that i did wear 3 pieces, to be sure i have set bonus of the correct cain set. Other thing is which i have anyway confirmed now is when someone else is wearing Cain set and im killing the boss, that other player got extra keys. But i dont know why its not the case with me…as the set bonus do say on drop and not kill.
EDIT: Another question…Do you have to be in the rift and do some damage on the boss or any trash mobs to get that chance of extra key?
Just kill 4 greater rift bosses at gr30 with someone else with both of ya with the set on and report how many keys both of ya got on each run, or post a build of the items you’re using when doing the greater rift.
That will make others believe you somewhat more, otherwise it’s just hot air like religion based on mythology.
You have to be nearby the boss at the time it dies. Are you now revealing that maybe someone else killed the boss whilst you were multiple screens away, on a different map level, or even stood in town?