Achievements Glitched?

Games Other Halo
1

I just did the Achivement “Kill an enemy with their own Plasma Grenade that is stuck to you in a matchmade game” I did that on a Anniversary map since the achievement is from the Anniversary DLC, but after I finally did it I didn’t get the achievement…

Video: Dropbox - File Deleted

2

I remember that one. I am not sure if you needed to do slight damage to the enemy first or not. I remember it was a pain to do and took many tries.