Solved❓ Causes for the 'dead-not-dead' enemy bug?

We've probably all seen the good ol' "I killed this Construct, but it healed as it died so it's still there yet invisible". I know you can walk so that it's out of your render distance, re-approach it and it'll be visible again, but aside from an enemy being healed - what are some main causes for this?

Recently made a Paladin, running Auto-ability, and running through Abysses, yet even some of the brutes would encounter this glitch, eventually disconnecting me, despite their inability to heal.

Any theories on what's causing this, and how to avoid it? I haven't had this issue on any other classes running Abysses. But now I can't even get through a single Abyss without being disconnected.

--Edit-- My vague take on it is that, of course, my client thinks it died at some point. I just can't work out if it's because a self-buff wasn't registered to the server somehow, or if it's possible that some XML has an outdated health value for an enemy. I'm stumped.

--Edit 2-- Disabling Auto Ability appears to have fixed the issue. Though, my curiosity is still piqued - if this is due to auto-ability, where is the "inconsistency" that caused the dead-not-dead?