There can be various reasons why your domain authority has dropped. Here are some possible reasons:
Poor link profile: If you have low-quality or spammy backlinks pointing to your website, or if you have been engaged in black-hat SEO practices such as link farming, then your domain authority may drop. Google sees these types of links as a red flag and will penalize your website.
Changes to the algorithm: Google updates its search algorithms frequently, and these updates can impact your website's ranking and domain authority. If your website is not aligned with the latest algorithm updates, your domain authority may drop.
Content quality: If the quality of your website's content has decreased, then your domain authority may drop. Google's algorithms look for relevant, high-quality, and meaningful content that meets the needs of searchers. If your content is not meeting these criteria, your domain authority may suffer.
Website structure: If your website structure is not optimized for search engines, then your domain authority may drop. Google prefers websites with clear and logical structures that make it easy for users to navigate and for search engines to crawl.
. Competition: If your competitors are performing better in terms of SEO, producing more quality content, and earning higher-quality backlinks, then your domain authority may drop relative to theirs.
To improve your domain authority, you should focus on building high-quality backlinks, producing relevant and meaningful content, optimizing your website structure, and staying up-to-date with the latest algorithm updates.