Cause
The issue is caused by the fact that fully qualified domain name (FQDN) of the container can be not resolved to IP by the service container.To verify it run this command on the node:
nslookup server.domain.tld
where server.domain.tld is FQDN of the container.
Resolution
To fix the issue make sure that the service container has DNS servers configured in IP configuration of its network adapter and is able to reach the DNS servers.
Also, please ensure that a Valid FQDN is set as the Plesk Hostname.
