All of my machines are set to directly use the pi-hole device as the DNS server but inside the pi-hole interface I can only see the router as being reported for all of the queries. Plus I also have errors when sending the some dns forwardings to my local active directory, some dns names are not resolved.
My DNS server inside the router for the DHCP server is set to the pihole ip, the clients report that they use pihole based on the ip. I have had this issue, I tried to reinstall the pihole on the raspberry, and I even updated to the beta. The issue is still there.
There’s something funky going on over there as per your debug log:
*** [ DIAGNOSING ]: Name resolution (IPv4) using a random blocked domain and a known ad-serving domain
[✗] Failed to resolve tracker.twenga.nl via localhost (127.0.0.1)
[✗] Failed to resolve tracker.twenga.nl via Pi-hole (192.168.88.9)
[✗] Failed to resolve doubleclick.com via a remote, public DNS server (220.127.116.11)
*** [ DIAGNOSING ]: Name resolution (IPv6) using a random blocked domain and a known ad-serving domain
[✗] Failed to resolve spaceclie.brunor0v.beget.tech via localhost (::1)
[✗] Failed to resolve spaceclie.brunor0v.beget.tech via Pi-hole (2a02:2f04:c:550a:1390:9ef6:d3f6:3149)
[✗] Failed to resolve doubleclick.com via a remote, public DNS server (2001:4860:4860::8888)
I do see some PHP errors too and what seems to be a non conventional interface
I updated my raspberry pi with "sudo apt-get update" and "sudo apt-get upgrade" and it removed something, some links. Now if I do pihole -r and I do a repair the PHP part is blank. Tomorrow I will try and reflash the whole raspberry to see if it fixes anything.