OpenShift 4 Authentication - failed to load SNI cert and key - Cluster API server unavailable after API certificate update

Issue

• After updating the API and Ingress certificates, the API and Console became unavailable.
• OpenShift oAuth API server cannot connect to etcd.

• Authentication pods stuck in CrashLoopBackoff state and shows a message like the following ones:

  failed to load SNI cert and key: tls: found a certificate rather than a key in the PEM for the private key
  

  failed to load SNI cert and key: tls: failed to find any PEM data in certificate input