Persistent Aoe after mob death

After the recent large patch it had seemed to have gone away, but today with the small patch it's come back. Unsure if rare monsters are intended to leave behind huge patches of aoes after they die.

These are elemental aoes left behind by the minions of rare monsters with either a "periodically unleashes (element)" or "periodic (element) explosions" (which is to say I don't remember which it is specifically, as one of them causes this and the other doesn't.)

They were temporarily disabled in a hotfix a while back because the telegraphs would become invisible if the minions' corpses were destroyed, through, say, shattering, causing the dangerous explosions to occur with essentially no warning in the location they died.

The patch re-enabled this on-death effect after fixing the issue that caused them to become invisible. And thus I must once again watch where I stand as I map. Alas.

Ah! I see. Thank you for the clarification. I'm not bothered either way, but it was nice to not have to worry about them lol.