Docker cant resolve DNS-Names outside of docker network. Receiving "read from DNS server failed"
I have the exact same issue. A dockerized adguard which works perfectly for everything except for other docker hosted on the same Raspberry.
From the other docker i can ping the adguard, i can access the port 53. From the adguard in debug i see the request coming in, i see no error, but no response going back to the docker.
Weirdly, in the log of the Adguard, i see that it has correctly dealed with my DNS request but the client IP adress is not from the orignal docker, but it is the IP of the adguard itself.
Finally if it tried an nslookup with the google DNS it works perfectly.
As i understand, it look like that the adguard server is answering the DNS request on its own ip and not on the orignal source IP.
Edit : I have been able to solve my issue by using macvlan networks on all my docker.