Same issue. After following the steps above the agent does change but data is not sent to elastic cluster.
On the workstation side I do see a connection is being established but dies very quickly. From the log
//
{"@timestamp":"2020-08-27T20:06:36.8385000Z","agent":{"id":"removed","type":"endpoint"},"ecs":{"version":"1.5.0"},"log":{"level":"info","origin":{"file":{"line":1392,"name":"HttpLib.cpp"}}},"message":"HttpLib.cpp:1392 Establishing GET connection to [https://myclustername:9200/_cluster/health]","process":{"pid":4140,"thread":{"id":7080}}}
{"@timestamp":"2020-08-27T20:06:36.55357800Z","agent":{"id":"removed","type":"endpoint"},"ecs":{"version":"1.5.0"},"log":{"level":"notice","origin":{"file":{"line":65,"name":"BulkQueueConsumer.cpp"}}},"message":"BulkQueueConsumer.cpp:65 Elasticsearch connection is down","process":{"pid":4140,"thread":{"id":7080}}}
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Connection is dead before anything is sent.