Sudden Loss of HP

[Tera]

IGN: Tera
Job: Bowmaster
Job Level: 250
Description of Bug (Explain the bug, How is it done, what should it really be doing? etc. An unclear description will not get the bug fixed):
I just somehow lose x amount of my HP out of nowhere which shouldn't be the case since I'm not getting hit at all (shown in the vid).
Screenshot (If Applicable):
At the 0:24 mark my hp goes down to approx. 11k from 40k

And in this video I lose about 10k hp at the 0:18 mark

 

[bawa]

this happens to me as well

job: dual blade

 

[Hene]

It's been a thing for months but no real clue what causes it :\

 

[Yuria]

This thread is about losing 1 entire chunk of your HP randomly, and not about the "losing HP the moment character was made" issue. For that please go make a ban appeal instead.

Tera has posted about this previously from the old forums, however this does not appear to have been resolved.
IGN: Maribelle / Ouka
Job: Jett - 244 / WA - P2

Description:
This has been an issue for a very long time, and has been observed by multiple members. In short, player HP occasionally drops to dangerously low levels for no apparent reason.
My HP is 74439 after buffs, and I was afking, yet my HP instantly fell to 7038 without me doing anything. I've observed this happening in all sorts of weird places, be it sitting down in towns, sitting down in FM, sitting down in monster maps, attacking, moving around and so on.
I cannot provide video evidence because this cut happens at completely random times and I do not know when it will happen again.
This is quite a problem if such random HP occur in high-damage maps such as pdung, where touch damage can go up to 20k.

 

[Alviss]

And in this video I lose about 10k hp at the 0:18 mark

My HP is 74439 after buffs, and I was afking, yet my HP instantly fell to 7038 without me doing anything. I've observed this happening in all sorts of weird places, be it sitting down in towns, sitting down in FM, sitting down in monster maps, attacking, moving around and so on.

Probably something with the "Auto casting skill" from pets.
From what Yuria said and Tera's video, this seem to be the only thing that make sense imo.