The issue here is that Zerto sees the new protected disks on the VMs, creates new mirrors on the Recovery site, and starts to sync then. Before the disks can be synced fully, they are pulled from the VM. Therefore, there are missing configuration details (disks) on the protected VM to get this VPG back into sync. Hence, Needs Configuration status.
If the affected VPG only has the 1 VM acting as a VEEAM proxy server, recreate the VPG.
If the affected VPG has many VMs, simply remove the 1 VM acting as a VEEAM proxy server, save the VPG, then edit once more and add the VM back in.
Ensure all VMs in the affected VPG are not being used as a Proxy Server for VEEAM or other 3rd party backup solution.