I have a bunch of docker containers running network services. Each one has a globally routable IPv6 address. They're behind a firewall so that's fine. It does mean I can refer to them by name rather than IP address though, without needing multicast DNS.

I have spent WEEKS wondering why my iPhone and Mac struggle to connect to them.

Apple is being "helpful" by trying to proxy non local sites to avoid trackers.

The proxy can't reach them.

Because they're on my LAN.

Which is behind a firewall.

I turned the tracker prevention off and Everything. Just. Worked.

RATFSCKERS!