Failure Scenario – Whole VMware cluster unavailabl

Hi, we have just implemented 2 new ESXi clusters and have been doing some power failure tests. Our concern is when we tested a complete cluster failure ( loss of power to site) Zerto did everything it was meant to, failed over to the still active site and started the protected VMs on the only cluster available, all good so far!
When power was restored to the failed cluster (what was protected site) the protected VMs on the failed site all powered on which then meant we had 2 of each VM running on different clusters and IP conflicts etc. Is there a function within Zerto or VMware that would stop the restored power cluster from not powering on what was the protected VMs on wat is now the secondary cluster?

Thanks