Hi,
First of all , i i would suggest you confirm if the group policy was applied successfully.
You can check that by running cmd as administrator and type command :gpresult /h report.html
Or you can check if the audit was enable by the command on NPS:
auditpol /get /subcategory:"Network Policy Server"
The output should be:
System audit policy
Category/Subcategory Setting
Logon/Logoff
Network Policy Server Success and Failure
If it shows ‘No auditing’, you can run this command to enable it:
auditpol /set /subcategory:"Network Policy Server" /success:enable /failure:enable
Best Regards,