why does myopia still progress in school-aged children?

please answer this question (If myopic defocus is effective in reducing axial elongation and myopia development, why does myopia still progress in school-aged children? Once the eye is myopic, shouldn’t the myopic defocus in the front of the retina (when uncorrected) prevent further axial elongation and myopia progression?) I will attach some article that may help you to answer the Question