Seemingly overnight my default web page via Safari on MacOS is showing ads as if PiHole does not exist. I can see that PiHole (v5.11.4) (FTL V5.16.1) has an explicit blacklist entry for GoogleAdServices.com but the ad gets though anyway. This Mac directly references the pihole on it's IP address for DNS.
Pi_OS: Raspbian GNU/Linux 9.4 (stretch)
Pi-hole version is v5.11.4 (Latest: v5.15.5)
AdminLTE version is v5.13 (Latest: v5.18.4)
FTL version is v5.16.1 (Latest: v5.21)
Okay, I probably need to update the Raspian version.... but I wonder why this stopped working when the settings seem to be proper.
Have you enabled iCloud Private Relay? If so, this will result in Safari using a DNS server other than Pi-hole.
But, first let's check the DNS servers actually in use by your Mac. From the Mac terminal (and not via a ssh session to the Pi-hole host platform), what is the output of the following command?
scutil --dns | grep nameserver
And also from the MacOS terminal, what is the output of the following:
nslookup GoogleAdServices.com
Stretch has not been supported by either Debian/Raspbian or Pi-hole for quite a while now.
Please upload a debug log and post just the token URL that is generated after the log is uploaded by running the following command from the Pi-hole host terminal: