A tls handshake error on fleet server

I'm running fleet agent on Nomad environment. The logs giving this error

http: TLS handshake error from x.x.x.x:yyyy  EOF\n","component":{"binary":"fleet-server","dataset":"elastic_agent.fleet_server","id":"fleet-server-default","type":"fleet-server"}

Any ideas how to solve this issue?
the fleet agent is register and running under Kibana Fleet UI section.

From Elasticsearch to Elastic Agent