Why are my services not registering with Jaeger?

Question

I have deployed two services in kubernetes (bare-metal k0s. To do some tracing on Jaeger Service A makes a call to Service B for a JWT authentication token - this works perfectly when I test in Visual Studio (Service A is able to retrieve token from Service B).

However when I execute the call in Postman now that I have deployed to k0S , I cannot see neither the services or any traces Jaeger UI :

Using guide from here I have configured the services as below :

Service A (Startup.cs)

public class Startup
{
    private readonly IWebHostEnvironment _environment;
    public Startup(IConfiguration configuration, IWebHostEnvironment environment)
    {
        Configuration = configuration;
        _environment = environment;
    }
    public IConfiguration Configuration { get; }
   
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddControllers();
        services.AddDbContext<ModelContext>(o => o.UseOracle(Configuration.GetConnectionString("OracleConn")));
        services.AddCors(c =>
        {
            c.AddPolicy("AllowOrigin", options => options.AllowAnyOrigin());
        });
        services.AddTransient<IAsyncAccountService<SttmCustAccount>, AccountService>();
        services.AddTransient<IAsyncLookupResponse, LookupService>();
        services.AddOpenTracing();
        services.AddSingleton<ITracer>(cli =>
        {
            var serviceName = cli.GetRequiredService<IWebHostEnvironment>().ApplicationName;
            Environment.SetEnvironmentVariable("JAEGER_SERVICE_NAME", serviceName);

            if (_environment.IsDevelopment())
            {
                Environment.SetEnvironmentVariable("JAEGER_AGENT_HOST", "localhost");
                Environment.SetEnvironmentVariable("JAEGER_AGENT_PORT", "6831");
                Environment.SetEnvironmentVariable("JAEGER_SAMPLER_TYPE", "const");
            }        
            ILoggerFactory loggerFactory = cli.GetRequiredService<ILoggerFactory>();

            ISampler sampler = new ConstSampler(sample: true);

            ITracer tracer = new Tracer.Builder(serviceName)
                .WithLoggerFactory(loggerFactory)
                .WithSampler(sampler)
                .Build();

            GlobalTracer.Register(tracer);
            return tracer;
        });           
      
    }

 
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseRouting();

        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });
    }
}

Service B has the exact same configuration.

Jaeger operator is set up using NodePort with config as in this file :

[file][https://drive.google.com/file/d/1nAjQ2jHrLSZLWoV9vGb3l4b0M1_yTMTw/view?usp=sharing]

I have to tried to expose the operator as Traefik Ingress but failed and had to change to NodePort (Can this affect registering of services , if at all ?) :

This is the call in Service A that retrieves token from Service B :

    [HttpGet]
        public async Task<IActionResult> GetAccountAsync([FromQuery] AccountLookupRequest request)
        {         
             string authenticationResponse = await GetTokenAsync();           
            if (authenticationResponse != null)
            {
                _logger.LogInformation("Called AccountLookup API");               
                List<AccountLookupResponse> res = new List<AccountLookupResponse>();
                var tranRef = String.Format("{1}{2}{0}", Helpers.aa, Helpers.bb, DateTime.Now.ToString("yyMMddHHmmss"));

...
}
}



 static  async Task<string> GetTokenAsync()
    {           
        var payload = "{\"Username\": \"golide\",\"Password\": \"It@XXXXX\"}";
        Uri uri = new Uri("http://10.XXX.XXX.XXX:31306/users/authenticate");
        HttpContent c = new StringContent(payload, Encoding.UTF8, "application/json");
        AuthenticationResponse responseEntity = new AuthenticationResponse();        
        var response = string.Empty;
        using (var client = new HttpClient())
        {
            HttpResponseMessage result = await client.PostAsync(uri, c);
            if (result.IsSuccessStatusCode)
            {
                response = result.StatusCode.ToString();
               // responseEntity = JsonConvert.DeserializeObject<AuthenticationResponse>(response);
            }
        }
        return response;
    }

In Postman context the call to http://10.170.XXX.XXX:30488/account?field4=3025202645050&field7=GENERIC01&field10=ABC076 will implicitly invoke the AuthenticationAPI at http://10.170.xxx.xxx:31306/users/authenticate

UPDATE Container logs show that trace-id and span-id are being generated :

[02:54:03 INF] Executed action method 

FlexToEcocash.Controllers.AccountController.GetAccountAsync (FlexToEcocash), returned result Microsoft.AspNetCore.Mvc.OkObjectResult in 416.2876ms.
[02:54:03 WRN] Event-Exception: Microsoft.AspNetCore.Mvc.BeforeActionResult
System.NullReferenceException: Object reference not set to an instance of an object.
   at System.Object.GetType()
   at OpenTracing.Contrib.NetCore.AspNetCore.MvcEventProcessor.ProcessEvent(String eventName, Object arg)
   at OpenTracing.Contrib.NetCore.AspNetCore.AspNetCoreDiagnostics.OnNext(String eventName, Object untypedArg)
   at OpenTracing.Contrib.NetCore.Internal.DiagnosticListenerObserver.System.IObserver<System.Collections.Generic.KeyValuePair<System.String,System.Object>>.OnNext(KeyValuePair`2 value)
[02:54:03 INF] Executing ObjectResult, writing value of type 'FlexToEcocash.Models.ResponseModels.AccountLookupResponse'.
[02:54:03 INF] Executed action FlexToEcocash.Controllers.AccountController.GetAccountAsync (FlexToEcocash) in 421.8383ms
[02:54:03 WRN] Span has already been finished; will not be reported again. Operation: HTTP GET Trace Id: c976e25bf21bfae5 Span Id: c976e25bf21bfae5
[02:54:03 INF] Executed endpoint 'FlexToEcocash.Controllers.AccountController.GetAccountAsync (FlexToEcocash)'
[02:54:03 INF] Request finished in 426.0567ms 200 application/json; charset=utf-8
[02:54:03 WRN] Span has already been finished; will not be reported again. Operation: HTTP GET Trace Id: c976e25bf21bfae5 Span Id: c976e25bf21bfae5

What am I missing ?