pi hole can't resolve local host names with forward lookup

[Bucking_Horn]

@simplifyandaddcoffee

since it is not getting an address via DHCP, is is not inheriting the suffix .home.arpa from the router. It was still self-identifying as sparq.local.
(...)
Is there a way I can set the suffix to home.arpa like the rest

You can either define a DHCP lease reservation for your Pi-hole RPi in your router and have Pi-hole request its IPv4 address via DHCP (by commenting out the static interface definition from your RPi's /etc/dhcpcd.conf).

---

Or you could add that option to your static network interface definition in /etc/dhcpcd.conf, right below the DNS servers, e.g. to read similar as:

interface eth0
        static ip_address=10.0.0.2/24
        static routers=10.0.0.1
        static domain_name_servers=127.0.0.1 8.8.8.8
        static domain_name=home.arpa

However, that would just make your RPi aware of a search domain.

As mentioned before, you'd still need to define the appropriate DNS records for both the plain as well as the FQDN, i.e. sparq and sparq.home.arpa.

You could either do that by adding multiple Local DNS records or by editing your hosts file as deHakkelaar has described above (EDIT: just be sure to do so for all relevant IPs).

---

If you want to stick with Pi-hole as DHCP server, you may also consider a related post in Clients unable to resolve Pi-Hole hostname - #9 by Bucking_Horn.