Cantilever umbrellas sway not due to a defect, but rather as a mechanism to alleviate wind pressure on the structure. This is an intentional aspect of their design; without this feature, they would be at risk of toppling or sustaining damage. Ideally, these umbrellas should not be set up in areas with high winds or in exposed locations. If you find the sway to be excessive, you may consider options to secure the parasol to the ground or to another structure, such as a fence, by utilizing a "wind stabilizer," which can be purchased from online retailers.