Trial of chaos, enemies protected by energy shield

I took the "debuff" which gives the enemies in the trial of chaos energy shield.
On the normal, magic and rare mobs it felt fine.
On the boss however it feels like the energy shield values are about 10 times higher than what they should be. I could whack the enemy with no poor usage of skills and in 30 seconds I'd only remove around 5% of the energy shield buffer.
Titan lvl 39. Relatively decent gear.

Reference number 843139056.
I also video recorded the encounter after I noticed this which I can submit if needed.

I can confirm as well, not only is the amount extremely large, but also it resets after a while to full HP, when the birdman boss jumps into the air. Definitely feels not normal.

I ran into the exact same issue. It took 10 minutes to break the chemara type boss's energy shield. After it broke I did 10% of it's actual HP in a single combo.