Adding to above, I would advice against using/configuring a public domain name as a search suffix domain at home!
If you do, the public DNS records you've create for that domain wont resolve on your local network bc those queries wont be forwarded to upstream but blocked instead by below settings (those queries are considered "local"):
Your router does something similar.
And if you disable above settings, certain local queries that cant be answered by Pi-hole or router will leak to the public upstream DNS server(s) which is not desired.
You can configure a private sub domain instead like home below for the public domain dehakkelaar.nl:
$ sudo pihole-FTL dhcp-discover
Scanning all your interfaces for DHCP servers
[..]
domain-name: "home.dehakkelaar.nl"
$ dig +short @dns.google. dehakkelaar.nl.
85.17.60.100
$ dig +short @dns.google. home.dehakkelaar.nl.
$
That way queries for names intended for local at home will not escape your LAN.
And public records you've created for the public domain will still resolve at home.
But will require you to administer DNS records at two places for at home and public.