Move HTTP request with cert file from nodeJs to .NET not working

I try to move a request with certificate from an old system made with NodeJS to a new system using .NET 8.0.

Running the .NET code, however, I always get the following error:

The SSL connection could not be established

Here is my NodeJS code:

const Q = require('q');
return Q.Promise((resolve, reject) => {
    const options = {
      method: 'POST',
      url: ConfigPayment.kmobile.url + '/targetUrl',
      headers: {
        'cache-control': 'no-cache',
        'content-type': 'text/xml;charset=UTF-8',
        'SoapAction': '',
      },
      agentOptions: {
        ca: [
          fs.readFileSync('file1.pem'),
          fs.readFileSync('file2.pem'),
          fs.readFileSync('file3.crt'),
          fs.readFileSync('file4.crt'),
          fs.readFileSync('file5.crt'),
          fs.readFileSync('file6.crt')
        ]
      },
      strictSSL: true,
      body: xml
    }

This is my new .NET 8.0 code:

var _trustedCertificates = new X509Certificate2Collection();

var filePathList = new string[]
{
    Path.Combine(this.ProjectRootPath, "file1.pem"),
    Path.Combine(this.ProjectRootPath, "file2.pem"),
    Path.Combine(this.ProjectRootPath, "file3.crt"),
    Path.Combine(this.ProjectRootPath, "file4.crt"),
    Path.Combine(this.ProjectRootPath, "file5.crt"),
    Path.Combine(this.ProjectRootPath, "file6.crt")
};

foreach (var path in filePathList)
{
    if (File.Exists(path))
    {
        logger.LogDebug($"Files exists {path}");
        var cert = new X509Certificate2(path);
        _trustedCertificates.Add(cert);
    }
}

var handler = new HttpClientHandler()
{
    SslProtocols = SslProtocols.Tls12,
    ServerCertificateCustomValidationCallback = (msg, cert, chain, errors) =>
    {
        logger.LogDebug("ServerCertificateCustomValidationCallback called. Errors: {Errors}", errors);

        if (errors == SslPolicyErrors.None)
            return true;

        using var chain2 = new X509Chain();
        chain2.ChainPolicy.RevocationMode = X509RevocationMode.NoCheck;
        chain2.ChainPolicy.VerificationFlags = X509VerificationFlags.NoFlag;

        foreach (var c in _trustedCertificates)
        {
            chain2.ChainPolicy.ExtraStore.Add(c);
        }

        var serverCert = cert as X509Certificate2 ?? new X509Certificate2(cert);
        var isValid = chain2.Build(serverCert);

        foreach (var status in chain2.ChainStatus)
        {
            logger.LogDebug("Chain error: {Status} - {Info}", status.Status, status.StatusInformation);
        }

        return isValid;
    }
};

this.httpClient = new HttpClient(handler);
this.httpClient.DefaultRequestHeaders.Add("cache-control", "no-cache");
this.httpClient.DefaultRequestHeaders.Add("SoapAction", "");
this.httpClient.BaseAddress = new Uri("https://targetUrl.com/");

Does anyone know what I am doing wrong?