Temporal Rift (Chronomancer) unusable with reserved Spirit

The skill Temporal Rift acquired through the Chronomancer ascendancy is supposed to have 0 activation cost.

If you socket persistent buff support gems with a Spirit reservation cost like Vitality or Clarity into it while you have sufficient Spirit, these buffs are active and reserve their respective Spirit amount.

The skill Temporal Rift however becomes unusable if you do not have the reservation cost in unreserved Spirit on top.

This seems like unintended behaviour. The "cost" of the reservation is already subtracted from the Spirit pool. The skill itself is not supposed to have an activation cost.

Either the tooltip is wrong for showing no cost or the requirement for unreserved Spirit to activate the skill itself is a bug.

Bump.

Still not fixed.

Same there. Still not fixed