ppl are thinking it is getting active if you gained a concentration stack. whereas it is not. it's getting active if you used "concentration" skill (which gives 2 concentration stacks).
so... yes it's working well.
It's working "as intended". I would not use the word "well" for sure.
This ruby is one of the weakest in the entire psi grid, winning only over Gravikinesis, Solid Grasp and Outsmarted (which make a difference close to an empty cell).
It would be a questionable investment even for one ruby, much less for two.
Not balanced properly looks very much like requiring a fix to me.