Herald of Ice and Delirium

This is more of a question than a bug report (though I guess it could be both as I'm a PoE newbie that started with PoE 2). Is Herald of Ice working as intended within Delirium maps? Currently when the enemies die in a Delirium map they don't trigger any explosions from HoI. The skill says the following:

"

While active, Shattering an enemy with an Attack Hit will cause an icy explosion that deals Attack damage to surrounding enemies.

Wondering if this is intentional given the design of the enemies or if this is a bug. Based on the skill's description it would seem that they should be exploding. Thanks!

Wanted to bump this as this is important for the devs to know, and is effecting literally every spec using herald of ice.

I don't think it's a bug. Frozen enemies you kill shatter - but the freeze threshold on monsters in Simulacrum is really high. So you probably don't freeze them consistent enough to get your explosions.