Unknown SSL protocol error after activating trial license

Hello,

Regarding the following options in kibana.yml:

elasticsearch.ssl.certificateAuthorities: [ "/etc/ssl/certs/CA.pem" ]
elasticsearch.ssl.verificationMode: full

Could you please test elasticsearch.ssl.verificationMode: certificate ?
Could you please try the following from the Kibana machine and provide us the output?

curl -u elastic https://elastic-node1.domain.com:9200 --cacert /etc/ssl/certs/CA.pem -vvvv
curl -u elastic https://10.3.144.143:9200 --cacert /etc/ssl/certs/CA.pem -vvvv