Possible Bug on the mana on kill for atziri's splendour

How do the mechanics of mana on kill work? Should you get the mana instantly? I ask as I am using atziri's splendour and sometimes I see jumps in my mana, but I can't seem to correlate it with the deaths of enemies. Is this a bug or am I failing to understand the game? Thanks for the help.

Edit: In case it matters, I am using the energy shield variant of atziri's splendour and I kill using bladefall traps.

You are not getting the kills, your minestraps are(forgot what I read a minute ago). Perhaps sometimes getting kills with an orb of storms or other such self-skill? Those would give you a jump in mana,

I considered that. However, I am getting jumps in mana occasionally. which leaves me not convinced of that that is the explanation. (also don't worry about me too much) My mana is mostly fine. And so I just looked it up, you are right, traps are not supposed to give gain on kill. I am gonna guess my poison was what did it for me then. weird. my bad. sorry for wasting people's time.

Are you using any kind of damage over time effect? Technically you shouldn't get credit for any kills caused by traps/mines/etc. but if damage over time applied by a trap or mine is what kills a mob, you get credit for the kill.