Docker Swam 'DNSRR' 1.13 error

I’m running an ELK Docker Swarm with native ElasticSearch clustering enabled. To accomplish clustering natively, i set DNSRR on to ES once my service is created. I use NGINX to communicate from outside the network.

docker service update --endpoint-mode=dnsrr <servicename>_elasticsearch

Note that, it actually does work and enable ES clustering natively but throws this error whereas before it never did. what am i missing here?

unable to pin image elasticsearch to digest: errors:
denied: requested access to the resource is denied
unauthorized: authentication required