Comment 13 for bug 1917099

Yeah, I am very well aware of the RFCs and how delegation works.

The part that was missing from this bug report is you are trying to create secondaries off of these two zones on different servers.

So, the missing reproduction steps are:

1. openstack zone create --email <email address hidden> parent.example.com.
2. openstack zone create --email <email address hidden> child.parent.example.com.
3. openstack recordset create --record ns3.example.com. --record ns44.example.com. --type NS bb7af787-a6d7-48ad-a4b0-00f694c20ec6 child

Which gives you:
RecordSet belongs in a child zone: child.parent.example.com.

I think the issue you are running into relates to the pool configuration. Both of these zones are being added to the same pool (as in same pool of DNS servers). But you are attempting to split them.
I will look into this more tomorrow and comment again now that the scenario is more clear.