DNS SRV record support in apt
=============================
Apt supports a subset of the DNS SRV server records protocol as
described in [RFC 2782](https://tools.ietf.org/html/rfc2782) for service discovery.
Before connecting to the requested server APT will send a SRV
record request of the form `_$protocol._tcp._$host`, e.g.
`_http._tcp.ftp.debian.org` or `_http._tcp.security.debian.org`.
If the server sends SRV records
as a reply APT will use those to connect to the server(s) in
this reply. It will honor the `priority` field in the reply.
However it does not implement the `weight` algorithm as described
in RFC 2782. It will use an equal weight for each server of the
same priority.
If connecting to a server fails APT will retry with the next one
and remove the server from the list of valid servers for this
show original
$ cat /etc/apt/sources.list
[..]
deb http://deb.debian.org/debian bookworm main contrib non-free-firmware
deb-src http://deb.debian.org/debian bookworm main contrib non-free-firmware
$ dig +short _http._tcp.deb.debian.org srv
10 1 80 debian.map.fastlydns.net.
$ dig +short debian.map.fastlydns.net.
151.101.38.132
Below is a better example for the XBian distro based on Debian and offering three APT mirrors via those SRV records:
$ dig +short _http._tcp.apt.xbian.org srv
10 1 80 xbian-apt.mirrorservice.org.
10 1 80 apt.xbian.org.
10 1 80 apt1.xbian.org.
You could try create a debian.map.fastlydns.net. DNS record via the Pi-hole webGUI and point it to that US based IP you found.