When transferring accounts using the Live Transfer option if the source server is not authoritative for the domain been transferred the following error is presented:
This system is not authoritative for the zone “$domain-example.$tld”.
Note: $domain-example.$tld to be replaced with the actual domain in question.
This issue occurs when the source server does not have direct authority over the domain, meaning the DNS servers are remote (Not hosted in the same server as the domain).
To clarify, this is not a failed migration. The system is indicating it could not automatically change the records to match the new server and manual DNS intervention would be required.
Detailed information can be found in our documentation: https://docs.cpanel.net/whm/transfers/transfer-tool/#live-transfer
The simplest solution would be to re-transfer the account without the "Live Transfer" option enabled, or to simply manually update the DNS records.