Problems with Warzone Firefight bosses

Lately I’ve been playing firefight and (almost) every time I kill a boss I don’t get a medal for it. I mean I just played a game where I had my banshee stuck on a phaeton’s back and I was shooting it, I destroyed it and i didn’t get anything for it. Then I had the Halo 2 beam rifle and I was shooting a phaeton, it blowed up with my shot and still didn’t get anything. From 6 bosses I destroy in a match (example) I only get medals from 2 of them.
Even if I’m standing right in front of the boss shooting it and then destroying it I’m not getting ANYTHING. I don’t know if it’s just me or what but it pisses me off.

this happens all the time, i agree they need to give anyone who damaged the boss an assist for it and the person or people who did the most damage the kills for it