Burrowing claw prevents spiked gauntlet bleed effect

Not sure if this is intended, but with burrowing claws the spiked gauntlet mod does not proc despite being ostensibly unarmed. I was hoping for a fun double-bleed combo.

I have flaming ray, multiple heads, and multiple arms, and first hand is head hand, so first claw is flaming and on head-hand, and second claw is flaming on upper right hand. Doesn’t proc wearing guantlets on either set of arms.