Spiked Armour not Interacting With Armour Increases to Body Armour

Spiked Armour, which gives Thorns equal to 2% of the armour value from your equipped body armour, is not interacting with nodes that increase the value of your body armour's armour and Ancient Aegis.

This seems like it may be a bug because the synergy is pretty obvious to me, but I'd like to know if this is an intended result.

Not getting any thorns.

Edit: Nevermind its from body armour only, but very little. Would never be worth the passive point for a tier 1 modifier, even if you were going a build with a lot of reflective damage.