Incarnation of Dread/scarab of awakening invisible degen

While farming with scarab of awakening i noticed that when incarnation of dread was present, and it used the HUGE AoE (fire?)circle that you have to be inside it to not take damage, the whole area where the graphics effect for the AoE was present begins to degen my character, even after the boss is defeated.
its a huge area with nothing on the screen that just melts the characters hp/ES, looks like all the area where the damage was supposed to hit turns into an invisible lava pool that HURTS A LOT

Happened multiple times, consumed my xp bar a lot, had to change farm strategy because of this.

Dx12 low settings

+1
i want to curse but i try to hold it