Hextech Crafting Bug or Intentional?

Hello Guys,

I believe most of you would have checked out the new Hextech crafting feature which came with this patch. However, I was having one doubt if a certain thing was bugged or intentionally was meant to work like this.

IIRC, if somebody in a party makes S+, S, S- mastery in a match, everybody gets a Chest. However, from the experience, only me and the players who have the champ I was using gets the chest, not others.

For example:-

I am using Yasuo and have 3 members in party. 1 member have bought Yasuo as well.

I get S+ mastery in a match, only me and the 1 person who have Yasuo gets the chest. Not other members of party.

So was it meant to be like this or is a bug?