Confirmed Kill perk not working

I was playing a round of breakthrough on Manhattan Bridge through the breakthrough matchamaking and i noticed that the perk wasn't working since i killed an enemy engineer by headshot while having it active and he was revived instantly by the medic that was beside him, you can see the perk was active on the right side of the screen and also can confirm that it was a headshot from the kill mesage, the red skull and the kill feed, the weapon that i was using was the SV-98 Sniper Rifle with the SSDS 6.00X, Double Port Brake, the 730mm Extended Barrel and the Match Grade Ammo.