Armour Break II Does Not Work On Sunder

The Armour Break II gem is allowed to be applied to Sunder but does not break any armour when dealing physical damage. I tested it on other skills and it works fine. I have also verified that Sunder is doing physical damage. Seems bugged

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Payoff Skills have powerful extra affects when Hitting enemies inflicted with specific Debuffs, often Consuming the Debuff in the process. Payoff Skills cannot inflict the Debuff they interact with.

Sunder is a Payoff skill, so it cannot inflict armour break.

EDIT: This quote is from the Payoff tooltip.