EtcdCertSignerControllerDegraded error on etcd operator

Issue

• Following certificate error is returned when executing oc describe co etcd.
  • The same error message shows up multiple times, at least once for every etcd member.
  • Server names and IP addresses have been hidden.

Message:               EtcdCertSignerControllerDegraded: [SAN for the certificate <etcd_member_name> does not include <IP>: x509: certificate is valid for <IP>, not <IP>, SAN for the certificate [...]    
    Reason:                EtcdCertSignerController_Error
    Status:                True
    Type:                  Degraded