Last weekend, I noticed Google ads appearing everywhere, e.g. marketwatch.com, thehill.com and more. I saw that the oisd.nl list had changed, so I made that modification, did a clean install of Bullseye (was on Buster) and made sure Pihole was completely up to date. I'm still getting Google served ads, and some others too.
Here's my debug token https://tricorder.pi-hole.net/YtBtXELW/
Netgear Orbi router connected via IP passthrough to AT&T Fiber modem.
I had made no changes to Pihole or the network for months, nor last weekend.