VB.net httpclient receives Header OK 200, but content is empty - vb.net

Question

I use MS Visual Studio 2017 in Windows 10 and tried following httpclient by VB.net in order to get html of, for example, yahoo.com. I could get Header OK status 200 while its contents consists of several funny letters and finally resulsted in empty when converting to string.
Would you please advise how to receive contents by means of httpclient?
I tried variety sets of header which are not a cause of the problem. I assume the cause exists in how to convert the contents or I may need to access again the site after receiving a header in order to receive the content???.
Dim url As String = "https://yahoo.com"
Dim httpclienthandler0 = New HttpClientHandler()
httpclienthandler0.UseCookies = True
httpclienthandler0.SslProtocols = SecurityProtocolType.Tls Or SecurityProtocolType.Tls11 Or SecurityProtocolType.Tls12 Or SecurityProtocolType.Tls13
httpclienthandler0.ServerCertificateCustomValidationCallback = AddressOf OnRemoteCertificateValidationCallback
Dim httpclient0 As New HttpClient(httpclienthandler0)
httpclient0.DefaultRequestHeaders.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9")
httpclient0.DefaultRequestHeaders.Add("Accept-Encoding", "gzip, deflate, br")
httpclient0.DefaultRequestHeaders.Add("Accept-Language", "en-us;q=0.7,en;q=0.3")
httpclient0.DefaultRequestHeaders.Add("Cache-Control", "max-age=0")
httpclient0.DefaultRequestHeaders.Add("Connection", "keep-alive")
httpclient0.DefaultRequestHeaders.Add("Upgrade-Insecure-Requests", "1")
httpclient0.DefaultRequestHeaders.Add("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36")
httpclient0.Timeout = TimeSpan.FromSeconds(10.0)
Try
Dim res As HttpResponseMessage = Await httpclient0.GetAsync(New Uri(url))
res.EnsureSuccessStatusCode()
Dim responseBody As String = Await res.Content.ReadAsStringAsync()
Dim enc As System.Text.Encoding = System.Text.Encoding.GetEncoding("utf-8")
Dim html As String = String.Empty
Using stream = Await res.Content.ReadAsStreamAsync()
Using reader = DirectCast(New IO.StreamReader(stream, enc, True), IO.TextReader)
html = Await reader.ReadToEndAsync()
End Using
End Using
Catch ex As HttpRequestException
Dim ex1 As Exception = ex
While (ex1 IsNot Nothing)
Console.WriteLine("Ex Message: {0} ", ex1.Message)
ex1 = ex1.InnerException
End While
Catch ex As TaskCanceledException
Dim ex2 As Exception = ex
Console.WriteLine(vbCr + "Timeout!)
Console.WriteLine("Ex MEssage: {0} ", ex2.Message)
End Try
Following codes derived from above are specific code that gets empty contents.
Dim responseBody As String = Await res.Content.ReadAsStringAsync()
and I tried next code instead of responseBody.
Using stream = Await res.Content.ReadAsStreamAsync()
Using reader = DirectCast(New IO.StreamReader(stream, enc, True), IO.TextReader)
html = Await reader.ReadToEndAsync()
End Using
End Using
However both code resulted in empty.
Thank you indeed for your time to read and answer.