DNS Zone Errors - Active Directory Zone was not found/is not available

I have a client that I am trying to clean up and straighten out their DNS.  Running the DCdiag DNS test and BPA on each server brings up a number of errors, and I am at my wit’s end trying to resolve them.  DNS seems to be functioning correctly for the time being, but I want to resolve any issues ahead of my next project.

• The primary DNS Zone is called “domain.com”
• “domain.com” is a parent domain with 2 child domains – “child1.domain.com” and “child2.domain.com”
• All domains are contained in the Forest “domain.com” with 2-ways trusts
• There are 8 total DCs/DNS servers – 3 “domain.com”, 3 “child1.domain.com” and 2 “child2.domain.com”
• DNS Zones are Active Directory Integrated (though I am skeptical for the child domains)
• Replication is set to ALL DNS servers in this Forest
• There are no conditional forwarders configured

Best Practices Analyzer Results

• Error DNS:  The DNS Server <IPaddressOfClientDNS> on <primaryNIC> must resolve names in the primary DNS domain zone (error occurs for each DNS Server configured on the NIC).
• Error DNS:  Zone <child1 or child2>.domain.com is an Active Directory integrated DNS Zone and must be available.

There are no BPA errors on the 3 parent “domain.com” servers, only the “child1” and “child2” servers.

Each DC/DNS server has a single NIC, single IP address.  The client DNS servers are pointed at opposing DC/DNS servers within the same domain and the loopback is configured as a third option.

DCDiag DNS Test Results

• The SOA record for the Active Directory zone was not found (shows on all “child1” and “child2” DCs)
• Warning: The Active Directory zone on this DC/DNS server was not found (probably a misconfiguration)  (shows on all “child1” and “child2” DCs)
• Root zone on this DC/DNS server was not found (shows on all 8 DCs)

I am including a screen grab of the DNS tree structure.  I think the problems are related to the organizational structure and/or delegation, but this is over my head now.

• Note that “domain.com” shows a “zone” folder icon.  “child1” and “child2” are nested inside “domain.com” and have a standard folder icon.

Also note the delegated “_msdcs” folder under “domain.com” – contains 3 NS records for the “domain.com” DCs.  The “_msdcs” folders under the child domains are not delegated and contain no NS records – only a “dc” and “pdc” folder.