Multikill Bug?

I just got done with a BTB slayer match in which I killed three people in very quick succession and did not receive a triple kill medal, not even a double kill medal, in fact, I didn’t receive a single multikill medal the entire game. I found this very odd and was wondering if there was some change in the most recent multiplayer update, or if this is a new bug?

Edit: specifically, it was with the beam rifle which I got as an ordinance drop.