Called Shots Missing

I have selected the Called Shots Deadeye ascendency, but no longer see it in my skills menu. I first noticed that Falling Thunder was hardly doing any damage anymore, then I noticed that I had stopped generating charges like I had been previously, then finally noticed that no enemies were being marked.

Is this a bug, am I just overlooking something plainly obvious, or did I miss something in the patch notes?

Thanks!

I've tried unspeccing the node and reallocating it with Doryani, but there was no change.

I didn't have enough Dex for the gem that was allocated to the slot. It is fixed now. I do wonder if there is a better way to notify the player that the skill is there, but unusable due to requirements though.