At this point I am assuming that it is actually a docker issue.

Can you show your docker daemon configuration?

Hard to tell where it is on your machine. Try ~/.docker/daemon.json, or maybe /etc/docker/daemon.json… Else look for it haha

Well this is getting weird.

Have you tried checking if your os has a resolution cashe active? If so, try to flush it.

I have read the rest of the comments to see what you already tried. I was about yo tell you to use sysctl to disable ipv6 but it looks like that is already done.

As a matter of fact, it looks like you have no ipv6 address at all. Which makes me think that your DNS config might be off, as it shouldn’t even attempt an ipv6 resolution.

Can you show me the content of /etc/resolv.conf ?

Also install “dig” if you dont have it already and show the output of

dig registry-1.docker.io

What version of Pi OS are you running?

(we can move to DMs if you wish, it will be less polluting, or stay in the comment thread if you don’t feel safe in DMs)

Looks like your Pi thinks it can use IPv6. Find where, and disable it.

No, that’s if you use their hosted service. It’s free to self-host.

I have answered, and had to put “Other” in employment status because I am self employed. An option for self employment would have been useful in my opinion!