The page has a logical tab order
Being able to TAB through sites is important for keyboard and screen reader users. It's only if you add <script> to the site that this might be a problem.
If you get this error, check Custom Code or Element Settings > Custom Attributes.
Google Lighthouse says
Many different users rely on the keyboard to navigate applications, from users with temporary and permanent motor impairments to users who use keyboard shortcuts to be more efficient and productive. A logical tab order is an important part of providing a smooth keyboard navigation experience.