Frozen Locus and Cast on Crit

You can place Frozen Locus into a Cast on Crit Spirit gem. It does not trigger though. You cannot turn the Spirit gem on with Frozen Locus alone in it neither.

I pray to the PoE gods it's gonna be fixed so it works and is not just blocked from usage in the Cast on Crit. I know how it ends though.

Unfortunately frozen locus is an attack. Not a spell. Cast on X states "socketed spells". I was really hoping it could be used.