Mercenary - Bow & Crossbow. Primary left mouse button fire

I am having issues with Crossbow "Basic Bolts".
I cant fire Basic Bolts with my nouse left button.
However, bow works fine, but not crossbow.

On my mouse right click button, I have crossbow rapid or frost. Works great.
On my mouse left click button. I have Bow shot which works fine, but when I choose crossbow basic bolts. It wont fire & the character wont move.
What did I miss?

You need to have both "load (x) rounds" and "fire/shoot" on your skill bar

I know it's kind of unintuitive