Strict Certificate Validation will check against the normal certificate pinning used by the legacy certificate per normal operations, added with that it will check for expiration date. Windows sensors will also check for cert chain validation, hostname (SAN) and key usage.
Additional Information
This feature should only be used for custom CA certificates
Setting Strict Certificate Validation on legacy certificates will cause sensors to go offline
This is a global feature, setting this will affect all sensor groups regardless of certificate assigned to the groups
Only Global Administrators will be able to enable this feature
Windows XP, Windows Vista, and Server 2003 do not support TLS certificate swap
Linux sensors support CA certificates as of sensor version 6.3.0 and sever version 7.1.0. Earlier versions will use the default legacy certificate
macOS sensors support CA certificates as of sensor version 6.2.5 and sever version 6.4.0 Earlier versions will use the default legacy certificate