Collectible Card Game Headquarters

Not sure if there's a bug or something I'm missing, but I've got a patch with a number of cards ready, but noticed an issue in Forked Lightning. It correctly let me target 3 players, but it's only letting me assign a max of 3 damage instead of 4. I am currently using:
this.getSpellAbility().addEffect(new DamageMultiEffect(4));
this.getSpellAbility().addTarget(new TargetCreaturePermanentAmount(3));


This was the setup I've seen on other cards that deal divided damage. Not sure what would be at fault here, so throwing this out there in the meantime.