Posting news article not sending notification to Teams activity feed

Hello

I am trying to troubleshoot why when posting a news article it is not coming up in people's Teams activity feed.

• We have a hub of sites branded as the intranet but they are not news organisation sites. When news posts are published from any site in this hub, people are receiving notifications of news posts in their Teams activity feed. Eg. 'Joe Blogs published news'.
• On a stand alone communication site, I publish a news post, for the members of that site they do not receive the notification in their Teams activity feed.

Some facts

• We are not using Viva Connections - so there is no home site (no Viva license yet)
• No sites are news organisation sites
• Internet sites are not necessarily followed (most people do not follow) so this has no bearing on receiving notification in Teams
• Notification settings in Teams are not disabled for test users

What other steps can I take to investigate why this site not connected to the internet hub is not pushing notifications? It is one example of a site, there are many that do not push notifications as well.

Thank you.