Certificate based Authentication and KB5014754

This has become more important since the original question was posted. As of the September 9, 2025 Windows security updates, the temporary compatibility-mode registry workaround is no longer supported.

For certificates issued by Microsoft Enterprise CA templates, the preferred approach is to issue certificates that contain the SID security extension so the DC can strongly map the certificate to the AD object.

Existing certificates that don't meet one of the strong-mapping methods can fail authentication under full enforcement. Check the DC System log for certificate-mapping events and validate your templates before renewing certificates.

If you're using a non-Microsoft CA or certificates where the requester supplies the subject, you may need one of the supported explicit strong mappings instead.