Problem: The client is experiencing an issue where the browser tab titles, which use the placeholder %sitename% in Yoast SEO, do not display the correct sitename for translated pages. This problem affects all languages on the site and started after a recent update. Solution: We recommend updating the WPML SEO plugin to the latest version, 2.2.0, as the client currently has an outdated version, 2.1.1, which might be contributing to the issue. It is also important to ensure that the Yoast SEO plugins are updated to their latest versions.
Please check if the Blog Title has been correctly translated in WPML → String Translation. You can search for the original string and ensure the translation is added and saved properly for each language.
If the problem persists, please open a new support ticket for further assistance at WPML support forum.