Is HTTP EnrichWithHttpResponseMessage expected to be executed before all delegate handlers do their job?

[marcinjahn]

I register an HTTP client in my app, like this:

services.AddHttpClient<MyClient>()
   .ConfigureAdditionalHttpMessageHandlers(
            (handlers, _) => handlers.Add(new MyHandler(options))
        );

My handler:

public class MyHandler(MyHandlerOptions options) : DelegatingHandler
{
    protected override async Task<HttpResponseMessage> SendAsync(
        HttpRequestMessage request,
        CancellationToken cancellationToken
    )
    {
        HttpResponseMessage? response = null;

        try
        {
            response = await base.SendAsync(request, cancellationToken).ConfigureAwait(false);
        }
        finally
        {
// BREAKPOINT
            if (request.Content is not null && options.AttachRequestBodyPredicate(response))
            {
                var requestBody = await request.Content.ReadAsStringAsync(cancellationToken).ConfigureAwait(false);

                // do something with the body
            }
        }

        return response;
    }
}

I also add tracing:

        services
            .AddOpenTelemetry()
            .WithTracing(cfg =>
            {
                cfg.SetResourceBuilder(resourceBuilder);
                cfg.AddHttpClientInstrumentation(opt =>
                {
                    opt.EnrichWithHttpResponseMessage = (activity, response) => {
// BREAKPOINT
                       // some enrichment
                });

                cfg.AddOtlpExporter(options =>
                {
                    options.Endpoint = new Uri($"http://{tracingConfiguration.Host}:4317");
                });

                cfg.SetErrorStatusOnException();
            });

I set breakpoint within the EnrichWithHttpResponseMessage action and also in my delegate handler. I'd expect the breakpoint in delegate handler to be hit first. However, it's the EnrichWithHttpResponseMessage action that gets hit first.

Why is that?