@robcool Thank you for reaching out to us, As I understand you have a question related to ADFS application activity report.
After installing the Azure AD Connect health agent - https://learn.microsoft.com/en-us/azure/active-directory/hybrid/how-to-connect-health-agent-install#install-the-agent-for-ad-fs:~:text=aadcdn.msauth.net-,Install%20the%20agent,-To%20download%20and are you able to see ADFS health related data in the Azure AD portal ?
The AD FS application activity report lists all the AD FS applications in your organization with active users sign-in in the last 30 days - Are users actively accessing the applications ?
Also, the report doesn't display Microsoft related relying parties in AD FS such as Office 365. For example, relying parties with name 'urn:federation:MicrosoftOnline', 'microsoftonline', 'microsoft:winhello:cert:prov:server' won't show up in the list.
Reference: https://learn.microsoft.com/en-us/azure/active-directory/manage-apps/migrate-adfs-application-activity#:~:text=Can%27t%20see%20all%20my%20AD%20FS%20applications%20in%20the%20report
https://www.youtube.com/watch?v=PxLIacDpHh4
if these suggestions doesnt help to isolate your issue, lets connect offline to troubleshoot the same.
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