Rage 3 not generating rage

I have this socketed in furious slam and it seems that because slam is a rage spender, it doesn't generate any rage as it should. All other skills are generating rage from it being in furious slam as do the aftershocks from slam. A shame as I was hoping to replace maul with it completely.

Same problem. Don't understand why don't they fix this since E2025.

Rage III with Spearfield -> No generation.
"Gain 1 Rage on Melee Hit" on gloves -> No generation.

At least on the screen, there is no rage icon at all.