Dev vs Live Site
The most common scenario in which this happens is when the Dev site is being edited, and then the live site being reviewed. Changes made to a Dev site do not affect the Live or Production site. Confirm you are logged into the Live Site and not the Development or Test site.
Another scenario in which this happens is due to caching, either within your browser cache or from a caching plugin in the site.
Plugin Caching: If your site includes a caching plugin, typically used to speed up the loading of pages in WordPress, it's possible the cached version has cleared itself. This issue will resolve itself when the cache clears itself. If you have access to clear cache for the website, you may perform this manually.
- Locate the caching plugin for the site. This can vary between sites.
- Click the clear cache button. The language will vary between plugin types.