Rageforged + Armour Explosion

Using Armour Explosion and Rageforged on the same skill makes it so it spends 10 rage every time Armour Explosion is activated in a single skill use. I observed this using Stampede. Removing Armour Explosion just consumes 10 rage on skill activation like normal.

Same problem with Poisonburst Arrow and Bursting Plague with Rageforged. When enemies explode with plague they sap my rage. Seems like a rageforged supp gem problem?