I have Pi Hole v5.1 on my network doing DHCP and DNS. I used the web interface "disable" function this morning, instead of disabling ad blocking it seemed to completely disable DNS, meaning I couldn't resolve IP addresses.
Can anyone else reproduce this before I report a bug? It might be dependent on using Pi Hole DHCP. I use Pi Hole DHCP as the Fritzbox doesn't delegate IPv6 properly.