.NET: [Bug]: OTel is not emitted when invoking agent through AGUI

[viul-sc]

Description

STR:

1. Attach Otel

        ResourceBuilder resourceBuilder = ResourceBuilder.CreateDefault()
            .AddService("a2a-poc-service");
        _tracerProvider = Sdk.CreateTracerProviderBuilder()
            .SetResourceBuilder(resourceBuilder)
            .AddSource(SourceName)
            .AddSource("*Microsoft.Extensions.AI") // Listen to the Experimental.Microsoft.Extensions.AI source for chat client telemetry.
            .AddSource("*Microsoft.Extensions.Agents*") // Listen to the Experimental.Microsoft.Extensions.Agents source for agent telemetry.
            .AddConsoleExporter()
            ////.AddAzureMonitorTraceExporter(options => options.ConnectionString = config.GetRequired("APPLICATION_INSIGHTS_CONNECTION_STRING"))
            .Build();

2. Create AI Agent:

AIAgent agent = _chatClient
            .AsAIAgent(
                name: Name,
                description: Description,
                instructions: Instructions,
                tools: _toolRepository.Tools)
            .AsBuilder()
            .UseOpenTelemetry(sourceName: _otelConfig.SourceName)
            .Build();

app.MapAGUI("/", agent);

3. Invoke an agent through AGUI:

AGUIChatClient chatClient = new(new(), "http://localhost:5001");
AIAgent aguiAgent = chatClient.AsAIAgent();
await foreach (AgentResponseUpdate update in aguiAgent.RunStreamingAsync("Tell me a joke about a pirate."))
{
    Console.Write(update);
}
Console.WriteLine();

Expected:
OTel Telemetry logged to console.

Actual:
No telemetry logged:

Note:
If calling the same agent directly

await foreach (AgentResponseUpdate update in agent.RunStreamingAsync("Tell me a joke about a pirate."))
{
    Console.Write(update);
}
Console.WriteLine();

Then telemetry logged as expected:

Code Sample

<PackageReference Include="Microsoft.Agents.AI.A2A" Version="1.0.0-preview.260311.1" />
	  <PackageReference Include="Microsoft.Agents.AI.AGUI" Version="1.0.0-preview.260311.1" />
	  <PackageReference Include="Microsoft.Agents.AI.DevUI" Version="1.0.0-preview.260311.1" />
	  <PackageReference Include="Microsoft.Agents.AI.Hosting.AGUI.AspNetCore" Version="1.0.0-preview.260311.1" />
	  <PackageReference Include="Microsoft.Extensions.AI" Version="10.4.1" />

Error Messages / Stack Traces

Package Versions

1.0.0-preview.260311.1

.NET Version

No response

Additional Context

No response