Using an IP address (and port)

Cross posting from SO: https://stackoverflow.com/questions/69722698/using-an-ip-address-and-port

Ubuntu 18/Varnish 4.x

I'm not sure what I'm missing.

The documentation (http://manpages.ubuntu.com/manpages/xenial/en/man7/varnish-cli.7.html) seems to suggest:

...
backend.list [-p] [<backend_expression>]
  List backends.
...
Backend Expression
  A  backend  expression  can be a backend name or a combination of backend name, IP address
  and port in "name(IP address:port)" format.
...

However, I don't know if I'm missing something because I can't pass an IP address or port seemingly in Ubuntu 18 to list or set to auto/sick:

varnish> backend.list *www*
200
Backend name                   Admin      Probe                Last updated
xxx-www-5          probe      Healthy             5/5 Fri, 22 Oct 2021 08:36:34 GMT
xxx-www-5http      probe      Healthy (no probe)   Sat, 16 Oct 2021 18:52:41 GMT
varnish> backend.list *10.105*
200
Backend name                   Admin      Probe                Last updated
varnish>

Any ideas? Is this a documentation error and Varnish 4.x doesn't accept IPs?

Other relevant information:

Varnish config:

    ...
    backend xxx-www-5 {
            .host = "xxxweb05";
            .port = "xxx443";
    ...
    }
    backend xxx-www-5http {
            .host = "xxxweb05";
            .port = "xxx80";
    ...
    }
    ...

$ nslookup xxxweb05
Server:         127.0.0.53
Address:        127.0.0.53#53

Non-authoritative answer:
Name:   xxxweb05.xxx.com
Address: 10.105.xxx.xxx