Mobs in Simulacrum can't be shattered

Herald of ice never work in Simulacrum.
At first, I thought the threshold of the mobs was very high.
Then I found that even activating unbound avatar and wearing Polcirkeln Sapphire Ring make no difference.
Ice Bite shows on the bar, which means the mob is frozen. But killing them cause no explosion.

Just noticed the same thing, herald of ice just never procs in simulacrum on enemies due to their "assimilation" animation when they die.