Group boss blitz boss Bihyung have bugged mechanic. In 2nd phase there is mechanic where one player with selected color should kill spawned mob marked with white light. After that this player will obtain damage and he need to keep low HP for few seconds until boss will check it and finish this mechanic. If player have too much HP boss will kill everyone.
But this mechanic is bugged - game didn't detect player HP correctly and sometimes killing everyone even if marked player have low HP. As example - in my last attempt I got this mechanic twice.
I'm shai 10758 hp, first time at the end of mechanic I had ~3500 hp and mechanic was correctly - boss said marked player have low enough hp and no one died. Then I was marked 2nd time for this mechanic, I had ~2500 hp (lower than first time) but boss said that marked player have TOO much hp and killed everyone.

Please fix it ASAP because failing 'cause of game bugs is very demotivating.