Elemental Sundering unable to use skeletal frost mage freeze on minions

As the title says - the wording in both skills specifically states it can use freezes on allies, and skeletal mage ability specifically says it counts as a freezing ailment for the use of other abilities, yet it doesn't work at all.

can be replicated easily by simply using both abilities, and see it doesn't have any effect at all.

Any answer on this one? The skeletal brute consume freeze on them so it should work with elemental sundering too!