Ironwood Tincture stun on damaging hit does NOT work.

As title says, Ironwood Tincture does not stun on damaging hit.

Ironwood Tincture is in flask slot and highlighted indicating it's active.
Coated Blade ascendency within Magi tree is allocated.

Description of Ironwood Tincture:
"Damaging hits always stun enemies that are on full life."

I've tried spells, I've tried melee, I've tried bow skills.
All of these HIT a target at full life and do not stun.

I'm having the exact same issue? Is there no fix for this one yet?