Unbound and local area DNS

Is that with "conditional forwarding" enabled?

If so, tail the logs live with below:

sudo pihole tail

And run an nslookup on one of your clients (Windows, MacOS or Linux) while addressing one of those hostnames.

Eg:

C:\>nslookup hak01
Server:  ph6b.home.dehakkelaar.nl
Address:  10.0.0.4

Name:    hak01.home.dehakkelaar.nl
Address:  10.0.0.234
$ sudo pihole tail
[..]
Jul  4 18:15:48: query[PTR] 4.0.0.10.in-addr.arpa from 10.0.0.179
Jul  4 18:15:48: config 4.0.0.10.in-addr.arpa is <PTR>
Jul  4 18:15:48: query[A] hak01.home.dehakkelaar.nl from 10.0.0.179
Jul  4 18:15:48: forwarded hak01.home.dehakkelaar.nl to 10.0.0.2
Jul  4 18:15:48: reply hak01.home.dehakkelaar.nl is 10.0.0.234
Jul  4 18:15:48: query[AAAA] hak01.home.dehakkelaar.nl from 10.0.0.179
Jul  4 18:15:48: forwarded hak01.home.dehakkelaar.nl to 10.0.0.2
Jul  4 18:15:48: reply hak01.home.dehakkelaar.nl is NODATA-IPv6

Above you see nslookup does three types of queries from a Windows machine.
One reverse lookup (PTR query), one A record lookup (IPv4) and one AAAA record lookup (IPv6).

EDIT:

Oh Unbound isnt involved!
If setup correctly, Unbound only receives queries for public domains and not your private ones.

Client --> Pi-hole --[public domains]--> Unbound --> Authoritative DNS servers
              |
               ------[private domains via CF]------> Router