Failed to run Checking-internet-speed-with-Crew-and-Ollama

Describe the bug

https://github.com/tryAGI/LangChain/wiki/Checking-internet-speed-with-Crew-and-Ollama

I Change the code sample such as:
using System.Diagnostics;
using System.Net;
using LangChain.Chains.StackableChains.Agents.Crew;
using LangChain.Chains.StackableChains.Agents.Crew.Tools;
using LangChain.Providers;
using LangChain.Providers.Ollama;
using Ollama;
using static LangChain.Chains.Chain;
using static LangChain.Chains.StackableChains.Agents.Crew.CrewChain;

Console.WriteLine("Hello, World!");

//var model = new OllamaLanguageModelInstruction("mistral:latest",
// "http://localhost:11434",
// options: new OllamaLanguageModelOptions()
// {
// Stop = new[] { "Observation", "[END]" }, // add injection word Observation and [END] to stop the model(just as additional safety feature)
// Temperature = 0
// }).UseConsoleForDebug(); // we want to see what is going on
// 2. Create a model
var model = new OllamaChatModel(new OllamaProvider(options: new RequestOptions
{
Temperature = 0,
Stop = ["User:"],
}), "llama3.1:latest");

var pingTool = new CrewAgentToolLambda("ping", "executes ping on specified ip address", address =>
{
var addressParsed = IPAddress.Parse(address);
var process = new Process
{
StartInfo = new ProcessStartInfo
{
FileName = "ping",
Arguments = "-n 5 " + addressParsed,
RedirectStandardOutput = true,
UseShellExecute = false,
CreateNoWindow = true
}
};
process.Start();
string result = process.StandardOutput.ReadToEnd();
process.WaitForExit();
return Task.FromResult(result);
});

// controls agents
var manager = new CrewAgent(model, "manager", "assign task to one of your co-workers and return the result");

// the actual agent who does the job
var pinger = new CrewAgent(model, "pinger", "checks the speed of internet connection",
"you using ping command and analyzing it's result. After this you print a single number as your final answer(the connection speed in milliseconds).");

pinger.AddTools(new[] { pingTool });

var chain =
Set("What is my ping to google's main dns server?")
| Crew(new[] { manager, pinger }, manager);

// get response and send it as AI answer
var res = await chain.RunAsync("text", CancellationToken.None);
Console.WriteLine(res);

I got nothing: res

Steps to reproduce the bug

run the sample code , get nothing.

Expected behavior

No response

Screenshots

NuGet package version

No response

Additional context

No response

Start with the linked Checking-internet-speed-with-Crew-and-Ollama wiki example and run the posted C# sample using OllamaChatModel, CrewAgent, and chain.RunAsync. Trace the returned res value and the manager/pinger interaction; done means the sample produces the expected ping result, which should be clarified because the issue currently reports only an empty result.