A Microsoft Viva module that provides a gateway to a modern engagement experience.
Great to know that the issue has already been resolved and thanks for sharing the solution so that others experiencing the same thing can easily reference this! Since the Microsoft Q&A community has a policy that the question author cannot accept their own answer. They can only accept answers by others, I'll repost your solution in case you'd like to Accept the answer.
Case Title: Activity notifications in Teams when a news is posted to Viva connections not working
Issue Symptom: We've been using Viva Connections for some time and recently we stopped receiving notifications in the "Activity" tab in Teams when a news post is posted from Sharepoint.
Resolution: User need require the user to "Follow" the SharePoint site that posted the news.
Thanks for your understanding and support.