Spirit Reserve bug on Cast on Shock

https://imgur.com/YjLZyKf

I have Arc on cast on shock, I have 66 spirit, but i try to reserve it and it says not enough spirit, it should only cost 60 spirit. I have relogged, tried a didnt spirit gem, a different item that gives me spirit, same result.

Edit: figured it out, the skill linked to cast on shock had the box unticked for the weapon set.

I am also experiencing this issue. I have 60 spirit and it tells me I don't have enough spirit to active. I checked the weapon set checkbox and whilst both were empty, checking one or both makes no difference.

Tooltip is wrong, you need to equip a skill gem first in the Cast on X slot.

Common things to check for Cast on X:

1) Use a skill gem working with cast on X (a spell);
-For melee monk, Cast on Shock only works with Profane Ritual for exemple.-
2) Check if you have enough spirit available;
3) Check if you have the required stats on your character for all the gems;
4) Check if you have the right weapon set activated for the skills;
5) Check if you don't have a bricked gem with weapon set
(fix here https://www.pathofexile.com/forum/view-thread/3613166).

Hope it can help.