It's surprising that using a non-standard listening port will cause peers to actively avoid connecting to you, is it sensible to add this to the help message and the warnings on startup if people have changed the default? I can't find this behavior mentioned anywhere except for the comments in net.cpp. 

```
// do not allow non-default ports, unless after 50 invalid addresses selected already
if (addr.GetPort() != Params().GetDefaultPort() && nTries < 50)
continue;
```

https://github.com/bitcoin/bitcoin/blob/master/src/net.cpp#L1369

if (network_type == "onion") {
                const std::string truncated_bind_arg = bind_arg.substr(0, index);
                if (Lookup(truncated_bind_arg, bind_addr, BaseParams().OnionServiceTargetPort(), false)) {
                    connOptions.onion_binds.push_back(bind_addr);
                    continue;
                }
            }
        }
        return InitError(ResolveErrMsg("bind", bind_arg));
    }
    if (connOptions.onion_binds.empty()) {
        connOptions.onion_binds.push_back(DefaultOnionServiceTarget());
    }
    if (args.GetBoolArg("-listenonion", DEFAULT_LISTEN_ONION)) {
        const auto bind_addr = connOptions.onion_binds.front();
        if (connOptions.onion_binds.size() > 1) {
            InitWarning(strprintf(_("More than one onion bind address is provided. Using %s for the automatically created Tor onion service."), bind_addr.ToStringIPPort()));
        }
        StartTorControl(bind_addr);
    }
    for (const std::string& strBind : args.GetArgs("-whitebind")) {
        NetWhitebindPermissions whitebind;
        bilingual_str error;
        if (!NetWhitebindPermissions::TryParse(strBind, whitebind, error)) return InitError(error);
        connOptions.vWhiteBinds.push_back(whitebind);
    }
    for (const auto& net : args.GetArgs("-whitelist")) {
        NetWhitelistPermissions subnet;
        bilingual_str error;
        if (!NetWhitelistPermissions::TryParse(net, subnet, error)) return InitError(error);