Kibana oauth-proxy failing to reach OpenShift Container Platform - OAuth service after upgrade to 3.11

Issue

• The kibana pod is not working well. For some unknown (so far) reason, the proxy cannot access the oauth endpoint of the OpenShift Master:

2019/10/09 08:41:10 provider.go:542: Performing OAuth discovery against https://10.1.1.1/.well-known/oauth-authorization-server
2019/10/09 08:41:11 provider.go:583: GET https://10.1.1.1/.well-known/oauth-authorization-server Get https://10.1.1.1/.well-known/oauth-authorization-server: Service Unavailable
2019/10/09 08:41:11 oauthproxy.go:439: ErrorPage 500 Internal Error could not get login endpoint

• After updating to OpenShift Container Platform 3.11, I'm unable to access respectively authenticate in kibana.