I'm glad that you were able to resolve your issue and thank you for posting your 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.
Error Message:
Health service data is not up to date.
The AAD Connect health service is not receiving the latest data from the server listed above. This may be due to the connectivity issues or data collection issues on the server itself.
Issue:
You're using two Azure AD connect servers - one active and the other in staging mode. Within the staging server, AAD connect health services shows the above warning message. Because of this warning message, you'd like to know whether this is expected behavior.
Solution:
In order to resolve your issue, you were able to work with our Support Engineers and got the confirmation that the above behavior is expected and is normal for the staging server.
If I missed anything please let me know and I'd be happy to add it to my answer, or feel free to comment below with any additional information.
Additional Links:
- Troubleshoot data freshness alerts in Azure AD Connect Health
- Health service data is not up to date alert
- Azure AD Connect Health FAQ
I hope this helps!
If you have any other questions, please let me know. Thank you again for your time and patience throughout this issue.
If the information helped address your question, please Accept the answer. This will help us and also improve searchability for others in the community who might be researching similar information.