Falling sky rune skills capped damage

FALLING SKY- Glacial spike is capped at 409 ice damage. and damage is not increasing with max focus past that point. same with hail at 83 dmg.
doubled focus and still couldn’t get any damage numbers to increase past that point.

I had the same issue, but now I wonder if I just misunderstood the skill. Maybe you only deal more damage if your focus is full. I thought the damage scales with max focus, but I guess that would be too powerfull