"Add sub-domain DNS records to parent domain" does not work for sub-domains of add-on domains

DNS records of foo.main-domain.com is added to main-domain.com zone, however,
DNS records of foo.add-on-domain.com is not added to add-on-domain.com zone. A new zone is created for the subdomain.

See https://www.virtualmin.com/node/36883



Do all these domains have the same owner? Virtualmin will only add DNS records to a parent domain if it has the same owner as the sub-domain.

@JamieCameron: yes. all domains are created under the same account.

The problem is the "parent domain" concept. Virtualmin does not consider add-on(secondary) domains as parents.

Oh, I see what you mean. This is intentional - because it would add a dependency between the two child domains, which would cause breakage if the top-level domain was deleted. This isn't a problem when the parent domain is also the top-level DNS domain, as deleting the parent implies removal of all children.