Trouble tying down DNS Resolver (OpenWrt + pihole)


I recently started using OpenWRT
([LuCI openwrt-21.02 branch (git-22.046.85957-59c3392)] / OpenWrt 21.02.2 r16495-bf0c965af0)

and I also have Pi-Hole installed on a connected Raspberry Pi. I have made the following settings:
Interfaces>LAN>DHCP Server>Advanced Options>DHCP-Options to "6," (pihole IP)
Interfaces>LAN>DHCP Server>Advanced Options>IPV6 settings to piholes ipv6 address
Interfaces>LAN>Advanced Settings>Use customer DNS Servers to ""

PiHole is registering entries in the query log and I have identified certain ads that are blocked (IE:
PiHole is set to use Cloudflare for its DNS queries.

However, every website that checks what DNS resolver is being used (ipleak, top10vpn, mullvad) tells me comcast is my DNS Provider.

It seems incongruent because if PiHole is picking up entries on the query and openwrt is telling clients to use pihole, how is comcast getting pulled into the picture?

Any and all help is appreciated!

The info might be based on your public IP, not the DNS you use.