Area Damage passive nodes are wrong.

https://i.imgur.com/bj8caAh.png

Nodes in this cluster are called "Area Damage". But in the description it says that they increase area of effect by 12%, not damage.
This is clearly wrong, because they are surrounded by another cluster of nodes called "Spell Area of Effect" which increase area of effect by 8%.

I came here to report the same finding, and it looks like you already discovered the same issue.