Specifying NetworkInterface for HttpClient

Question

Ive been trying to create a .NET 6.0 program which uses a specific (Arch) linux network interface to make http requests for 2 days now, ive read #23267, tried understanding the code examples provided in it and many stack overflow solutions but none of them worked for me. I am also using IPv6 because for some reason both wlan0 (wifi) and enp3s0 (ethernet) have the same private IPv4 even though theyre on different networks, but this is apparently not too uncommon so since the IPv6's arent the same I went with them

Currently this is the code i have:

using System.Net.NetworkInformation;
using System.Net.Sockets;

foreach (var iface in NetworkInterface.GetAllNetworkInterfaces())
{
    if ((iface.Name == "wlan0"))
    {
        );
        foreach (var ua in iface.GetIPProperties().UnicastAddresses)
        {
            if (ua.Address.AddressFamily == AddressFamily.InterNetwork) continue; 

            Console.WriteLine($"\x1b[36m{ua.Address.AddressFamily} Address: {ua.Address.ToString().Split("%")[0]}\x1b[0m");

            HttpClient client = new HttpClient();
            client.BaseAddress = new Uri($"http://[{ua.Address}]:0/"); // same thing happens with splitting ua.Address

            try {
                var res = await client.GetAsync("https://ifconfig.me");
                Console.WriteLine(await res.Content.ReadAsStringAsync());
            } catch (Exception e) { Console.WriteLine(e.Message); }
        }
    }
}

The output of my program:

InterNetworkV6 Address: fe80::eaf:aec2:7d24:82d4
***.***.***.27

vs the correct wlan0 public IPv4 with curl --interface wlan0 ifconfig.me:

***.***.***.4

The client.BaseAddress part seems to do nothing, since i get the same result with and without it even though the IPv6 im specifying in the URI is definitely the wlan0 IPv6. So, trying another solution and rewriting the client:

HttpClient client = new HttpClient(new SocketsHttpHandler() {
    ConnectCallback = async (context, cancellationToken) =>
    {
        Socket socket = new Socket(AddressFamily.InterNetworkV6, SocketType.Stream, ProtocolType.Tcp);
        socket.Bind(new IPEndPoint(ua.Address, 0));
        socket.NoDelay = true;
        try
        {
            await socket.ConnectAsync(context.DnsEndPoint, cancellationToken).ConfigureAwait(false);
            return new NetworkStream(socket, true);
        }
        catch
        {
            socket.Dispose();
            throw;
        }
    }
});

This makes my program give this output:

InterNetworkV6 Address: fe80::eaf:aec2:7d24:82d4
No data available (ifconfig.me:443)

Now, testing on my laptop which also has Arch Linux installed, with 2 different wifi adapters where each is connected to a different network and has a unique private IPv4 address; One is a USB adapter and its called wlp0s20f0u2 and the other is the built in one, called wlp2s0. Changing my code from skipping IPv4 addresses to skipping IPv4 (the continue statements) and removing the AddressFamily specification from the Socket initialization - the plugged in adapter works fine and is the default option (gets chosen by a plain new HttpClient()) but the built in adapter ends up timing out after the default 100 seconds and i don't see any requests being made in the wlp2s0 interface through wireshark. This also happened on my PC with IPv4, before i somehow made both private IPv4's the same. And again, curl --interface wlp2s0 ifconfig.me works fine