Einhar's Beastrite gem bugged

So i get the feeling that this lineage support gem is currently bugged. I have it on the skill cull the weak. I am culling rare monsters with it and gaining the 2 modifiers. However if i cull another (not rare)monster with the skill while the 40 seconds of the stolen modifiers are not over yet they just dissapear. Is this intended or is this a bug? And are we able to stack modifiers with this if we kill multiple rares in a few seconds or is that not intended to be a feature of this gem?

+1. If the buff is overwritten on next kill of rare monster than this is marginally better than Behead II and not really worth the gem slot considering the hoops you have to jump through to meet the buff conditions. If it is the case that buff is overwritten then the gem text fails to include that information. If GGG thinks this gem is too powerful, like Headhunter, and overwrite is desired in their design, would rather see a cap on the buff limit to maybe 10 or 20 modifiers.

+1 Same issue, and had me confused until i noticed it vanished when i would cull other normal mobs. I hope that is not intended, if it is the gem is absolutely useless.

Further testing of this in 0.4 the problem is that culling any mob with the skill that has Einhar's beastrite socketed removes the buff.

To Replicate:

1)Equip Killing Palm and socket Einhar's beastrite
2) Find a rare, bring it down to cull range and use Killing Palm
> See buff appear in buff bar with duration of 5 mins
3) cull any blue or white mob with Killing Palm
> See buff immediately fall off

+1 I encountered the same problem in version 0.4, it's really frustrating

+1 same issue. it also appears to not steal 2 buffs all the time, even though the tooltip says it is suppose to steal two.

Same thing is happening using Shred / Lunar Assault on werewolf with no cull. Seems you cant use the skill at all after stealing a mod or it disappears or kill a mob with it. No wonder its 1 ex.

+1 Same problem, will remove it since I use it non stop to generate frenzy.