Essence Monsters dropping no Essences

Just ran a T16 Arena map with essences on it and an atlas tree specced into essences. I put an allflame ember of syndicate monsters who supposedly drop scarabs into the map as well. 2 of the imprisoned essences dropped no essences at all when i killed them. additionally the map did not drop a single scarab and i don't recall actually seeing any of the syndicate monsters in there.

Same thing happened to me now.
Glacier Map T8
Allflame for scarab drops.
Two Essence trapped monsters but no essences.

Same here, and I even got the achievment for killing monster with 8 essences and got none of them

Same thing. I did use a scarab allflame both maps that I saw it, not sure if related. Essence monsters show up but only about half of them dropped loot. It almost looks like the essence monsters are not being killed but rather poofing out of existence. I've double checked and removed filtering, didn't help.

I'm running scarabs and the passive for essence, I'm seeing all the essence monsters (should be at least 8 each time) but definitely not getting all the essences every time.