Is everything square? I’d probably verify again that all of the parts are perfectly squared up. All the bearings just touching. Everything moves very smoothly as you move it around by hand. Distance from printhead to surface of the bed is the same in all places or as close as you can make it. It may just be perspective in the picture, but I think my extruder is a bit different on the Cnc… if nothing else, slide the stepper in the extruder as close to the gantry as you can. Looks like there is a space there.