The Flame of Keld 3rd chapter not triggering for spells

The third chapter says “Spells in your hand gain ‘Deals 4 damage to your opponent.’ until end of turn.”

But after activating it none of my spells did did any additional damage.

Same thing happened to me. Did you have any creatures out? I think its another one of their multi-effects bug where not having all of the conditions means that none of them happen.