How does Purposeful Harbinger work? Why doesn't it affect my stats?

Hi,

The notable says "Aura Buffs from Skills have 8% increased Effect on you for each Herald affecting you, up to 40%". Apparently, it doesn't make any changes to my character stats (I tried toggling it on/off multiple times).

Below are 2 images illustrating the situation. I'm affected by Discipline. My ES sits at 5374 when turning it off and it doesn't change when turning Purposeful Harbinger on.

Purposeful Harbinger turned off
https://ibb.co/KykFffD

Purposeful Harbinger turned on
https://ibb.co/njBrFy0

Do you have another copy of Purposeful Harbinger in your build? Do you use any herald skill?

Edit: So I have checked your build, and you use several copies of Purposeful Harbinger. The limit of "up to 40%" is global affecting all copies of Purposeful Harbinger. You can get 40% with one herald and 5 copies or 1 copy and 5 heralds or a combination of two and three.

Since you use three heralds, you reach 40% with just two copies of Purposeful Harbinger, and the third is obviously wasted.

I understand, thank you very much for pointing that out! Have a lovely weekend.