The way to study a cantilever beam is to have a large blend radius at the base of the beam where it intersects a larger plate or solid block volume. Put the Fixed Support on the side faces of the solid block so that those faces are separate from the face of the block where the beam base intersects the block with the large blend radii.
Also, don't apply the force to the edge of the tip of the beam, apply it to the whole end face.