I dont think this is new as I have been noticing it more as I thinker and toy with cluster seeker mines.

I will occasionally leave one single NPC running around a combat zone and i've noticed that sometimes(not everytime) I will launch my cluster seeker mines and the NPC will take no damage. My seeker mines will blow up and occasionally I will see the yellow and orange damage number appears but the NPCs damage bar and or armor will remain unaffected.

Has anyone else noticed this?