Troubleshooting Yoast SEO Sitemap and Indexing Issues on Multilingual Sites

Many WordPress users rely on the Yoast SEO plugin to manage their sitemaps and help search engines index their content. However, a common and frustrating issue arises on multilingual websites: pages in secondary languages sometimes don't appear in the sitemap or fail to get indexed by Google. This guide will walk you through the most common causes and their solutions, based on community experiences.

Why This Happens

This problem is almost never a direct "bug" in the Yoast SEO plugin. Instead, it's typically a result of how multilingual plugins interact with Yoast, specific website configurations, or how Google's crawler interprets the site. The Yoast SEO plugin generates a single sitemap. For multilingual sites, it relies on the multilingual plugin (like Polylang or WPML) to correctly handle language variations through elements like hreflang tags and canonical URLs.

Common Solutions

1. Verify Your Multilingual Plugin Configuration

The first step is to double-check your multilingual plugin settings. Ensure that all translations are properly assigned and published. A missing translation link or an incorrectly set canonical URL can cause a page to be excluded from the sitemap or not indexed.

2. Check for Empty Archive Pages

Yoast SEO will automatically exclude empty archive pages (like categories or author pages with no posts) from the sitemap. This is standard behavior. Even if a category has posts in its subcategories, the parent category itself might be considered empty. If you need an empty archive page in the sitemap, you will need to add content to it.

3. Use Google Search Console for Diagnosis

Yoast SEO generates the sitemap, but indexing is ultimately controlled by Google. If your pages are in the sitemap but not indexed, the issue likely lies with Google's crawler.

• Submit Your Sitemap: Ensure you have submitted the correct sitemap URL (yoursite.com/sitemap_index.xml) to Google Search Console.
• Request Indexing: Manually request indexing for important URLs that are missing via the Search Console URL Inspection tool.
• Review Indexing Reports: Search Console will provide specific reasons why a page may not be indexed (e.g., "Crawled - currently not indexed"). This is the most valuable data for troubleshooting.

4. Ensure Proper Implementation of Structured Data

If you see errors about missing schema fields (like "offer" or "courseInstance"), this is not an issue with Yoast SEO. These errors are related to structured data added by other plugins, such as Learning Management Systems (LMS) or e-commerce plugins. You must contact the support team for that specific plugin to correct the schema markup.

5. Confirm Your Site is Fully Accessible

Search engines cannot index what they cannot crawl. Ensure your robots.txt file is not blocking important content and that your site does not use noindex tags on pages you want to be public. You can check individual pages by viewing the page source and looking for the meta robots tag.

When to Look Elsewhere

It's important to understand the scope of the Yoast SEO plugin. It only generates sitemaps for content within your WordPress installation. It cannot generate sitemaps for or help index content in subfolders that are not part of WordPress (e.g., yoursite.com/static/). For help with non-WordPress content, the Google Search Central Help Community is the best resource.

By methodically working through these steps, you can usually identify and resolve the barrier preventing your content from being sitemapped and indexed.