No Triple Kill?

So one of my tasks this week is 3 triple kills in tactical slayer. I had a double kill and melee the third (they were in a cluster so it was within 1-1.5 seconds) and I got all 3 kills (it was at the beginning of the game so I can see in my score total 3). But when I meleed the third, he also hit me and we both died…but despite getting all 3, I didn’t get a triple kill!!! There is 0 chance it lapsed the time frame since it was all so quick and they were clustered. What the heck???

It happens all the time. You’re often denied the multi-kill when a melee trade happens. It’s most likely because the other guy technically killed you a fraction of a second before. They still hand you the trade if you weren’t too slow, but you don’t get the multi.

Happened again today, but this time I got the achievement???