Ancestral Ferocity deals no damage?

Platform, device and operation system

What were you expecting to happen, and what actually happened
Tried to use the “Ancestral Ferocity” Barbarian spell, no damage while in Rage. Tried again multiple times in and out of rage, no damage. Does make the red gems though. Used both the Ultimate and the Spell on the same turn as well as waiting one turn before using as well, still ineffective.

How often does this happen? When did it begin happening?
Consistently only makes the gems without dealing damage.

Steps to make it happen again
Just having the spell equipped and using it in battle.