Support skills not being able to Double up

I can't equip a second support of Clarity 2, Vitality 2 or Cannibalism 2 on a second skill.

I have each of those on Herald of Ash already, and I want to put them on Berserk as well, for obvious reasons. But it gives me the old "Warning your character is already using this support gem"

But it will let me equip the lower versions of them Clarity 1, Vitality 1 and Cannibalism 1.

Seems like it is a bug, or maybe GGG didn't add in the skill note that says it is unique equip?

This is working as intended;

"

Timothy_GGG wrote:

Spirit reserving support gems are limit 1 globally for each rank of the support.

Source: https://www.pathofexile.com/forum/view-thread/3834300/page/1#p26307611