Creeping Frost's Chilling Area supported by Elemental Focus Support doesn't apply Chill

Let's take similar skills into account (Cold Snap & Vortex). Chilled ground from both skills apply Chill while linked with Elemental Focus Support (as it should be).

Cold Snap linked with Elemental Focus Support and Brutality Support:


Vortex linked with Elemental Focus Support and Brutality Support:




On the other hand, Creeping Frost's chilling area doesn't apply Chill while linked with Elemental Focus Support.

Creeping Frost linked with Elemental Focus Support and Brutality Support:


Bug or intentional? I noticed all three skills use different terms in skill's description:
Cold Snap (Chilled Ground)
Vortex (Whirling Vortex)
Creeping Frost (Chilling Area)