Authentication of [elastic] was terminated by realm [reserved]

Authentication of [elastic] was terminated by realm [reserved] - failed to authenticate user [elastic] | @timestamp=2022-11-23T07:21:04.573Z log.level=INFO ecs.version=1.2.0 event.dataset=elasticsearch.server[9cc768f0c53c][system_critical_read][T#1] elasticsearch.cluster.uuid=rjIYMrQ7QTeC9n03FL4KgQ

I'm running this on Docker: GitHub - deviantony/docker-elk: The Elastic stack (ELK) powered by Docker and Compose.

It've been running for a good while and has also been updated to 8.5.0 and 8.5.1 where credentials are created and stored on initialization.

I'm able to log in to Kibana and I see the logs ingested through Logstash, as expected.

So, this error regarding authentication, I'm not really sure why it pops up. Is there a way I can troubleshoot futher to see exactly what process is denied access and why?

Thank you very much for your support!