Still stucked. I have restarted my cluster, after adding xpack.security.transport.filter.enabled: false on each node, but the result is the same. Cannot connect the cluster. But I know the server is GREEN because I did receive an email from x-pack monitoring
root@wilco-1:~# nc -z -v -w5 localhost 9200
localhost [127.0.0.1] 9200 (?) open
root@wilco-1:~# curl -u elastic:3s3rqT102v0yZF0kHGdG http://localhost:9200
curl: (56) Recv failure: Connection reset by peer