Don't know, Don't care in IO patch

Hello, I'm, trying to finish this quest, we have already kill Behemoth Leader and got the quest ítem, after don't know how many kills we manage to kill Dragon Beast and got the ítem. This boss, Dragon Beast, after we lower his HP split into 3 bosses, with less hp, ok, that's not a problem, the problem is that randomly this boss spawn like 50 Death Knights or more, that hold, bleed making the raid close to imposible as all this debuffs stack on all characters.


Now we are trying to kill Drake Lord, but happens the same as with Dragon Beast, spawn tons of Death Knights.


Is this a bug? I mean, 2 of 3 bosses spawn this tons of mobs, and not the other one? Is this normal?


Any tip is welcome, ty in advance.