Why doesn't my host-mapped subdomain appear in search results? How long does it take for Google to reindex my new host-mapped subdomain?
If you have just host mapped your help center, it might take up to a few weeks for Google to reindex the new URL. This means it can take some time until the search engine results page of Google displays the new URLs. For more information, see this article from Google's help center: Get your website on Google.
If you want to test if your new host mapped subdomain was reindexed by Google and how many pages were indexed at any given point, use this search operator in Google: