The first place I would look is the termination points on the laser. They just wrap the wire on the posts and silicon them on, pretty sketchy. Any arching, even a small amount will reduce your power to the laser. Take them off and clean the posts with some sandpaper and re-strip the conductors. I then wrapped them on the posts and used a wire nut to hold them snugly. Don’t over tighten the wire nut as not to damage the post. Then re-apply the silicon topper that they used, or replace with a new one and re silicone.
Hope this works.