Your website's DA (Domain Authority) may not be increasing for several reasons. One reason could be a lack of high-quality backlinks. If your backlinks come from low-authority or irrelevant sites, they won't help much. Your website might not have enough unique or valuable content to attract links. Another reason could be poor on-page SEO practices, like slow page load times or duplicate content. If your website is penalized by search engines, your DA may not improve. Competition from other websites in your niche can also be a factor. Focus on improving content, backlinks, and site performance for better results.