In a scalable environment the expectation is to have multiple servers serving the content(s) to different regions(or sometime same region as well), the typical architecture is to have one content management server and atleast one content delivery server.
Sitecore provides “Sitemap XML module“, when we publish content(s) it will generate an updated Sitemap.xml file – basically, a listing of page(s) that a web-crawlers can use to crawl and index a site.
When we have content delivery servers set up as part of the configuration, we have to make sure that Sitemap.xml file also gets updated to CD servers which doesn’t happen by default, only content management file gets updated.
In order to make sure we Sitemap.xml file getting updated to the servers, we have to add following to events section:
<handler type=”Sitecore.Modules.SitemapXML.SitemapHandler, Sitemap.XML” method=”RefreshSitemap” />
This will updated the Sitemap.xml file in content delivery servers as well.
Note: Please refer this URL which explains about the same issue and resolution-
Happy learning 🙂