Twin stick shooter template: shoot at mouse?

I’m just making the jump over to Unreal from Unity — and, admittedly, I wasn’t very good at that yet either — specifically* for the blueprint system. (I’ve lost my ability to type code due to a worsening disability, and dictating code is downright painful.)

Anyway, I thought I would teach myself blueprints by making a simple shmup that I am physically able to play. Of course, very first thing I tried to do I hit a roadblock.

I thought I had figured out the logic. The template already calculates a vector from the stick axes, I thought I would just insert a new vector by taking the mouse position on screen, converted to world space, then calculate a vector towards it. But, it doesn’t seem to work. It just fires very slow projectiles in a downward direction with only slight variance in vector. (I’m guessing the slow part has to do with the z vector, but the rest I can’t figure out.)

*I did also fall in love with the level design tools once I found out about them.