sharepoint online – Manage what appears in "Site News"

I've changed "the state promoted" to a news page in 0 with the help of SharePoint Designer, then waited a moment and refreshed the page. Then this page is not in the News Web section on the page.

The news pages are displayed when they have been explored. You must wait for the next scan for the changes to take effect.

In SharePoint Online, the analysis is automatically performed according to the defined analysis schedule. And the time of exploration will increase if it is a heavy environment.

We can not manually run a full content scan or control analysis in SharePoint Online.
You can request a reindex of the library to resubmit the content for analysis.

Introduction to SharePoint Online Search and some troubleshooting steps:

https://techcommunity.microsoft.com/t5/SharePoint-Support-Blog/Introduction-to-SharePoint-Online-Search/ba-p/170708