Duplicate content is a common technical
SEO issue on Joomla websites, especially when the same article or page can be accessed through multiple URLs.
For example, Joomla can sometimes make the same content available through different menu structures, URL formats, domains, protocols, query parameters, or URL variations.
Google does not generally consider duplicate content on a website to be a spam violation. However, multiple URLs containing the same or very similar content can make it harder for search engines to determine which URL should represent the content in search results.