Fernando:
Welcome to the club and congrats on a beautiful bass. Your pickup screws aren't installed correctly. Alembic uses a brilliantly simple system. Two screws are supposed to be UNDER the pickup, (the entire screw, head and all), at opposite corners. The other two screws then go in OVER the pickup at the two other opposite corners. When properly set up, you should only see two screw heads on top of the pickup, not four. To adjust pickup height, you first loosen the two screws that are on top of the pickup, Then, using a narrow blade screwdriver that can fit through the screw holes, you adjust the two screws that are under the pickup to attain the desired height. Then you tighten the two screws above the pickup to lock it down in place. It's hard to tell from your pics, but it appears that some of your pickup screws may be longer than others. If this is the case, the shorter screws go under the pickup, and the longer screws are for the top of the pickup. I hope this helps.
Bill, the guitar one