HttpClient keeps receiving bad request

Okay, I figured out the issue I was having. It seems that Serializing my JSON object into a string first, then posting it with PostAsJsonAsync was leaving all of the escape (\) characters in my object, which was why I received the Bad Request.

The problem here was my first key/value pair in my JSON object had a key with the @ symbol in it. If I try to just PostAsJsonAsync with the object, I lost the @ symbol, which gave me a Bad Request also.

What I ended up doing was Serializing the object into a string as seen above, then I converted it the a Byte Array and then created a new ByteArrayContent object passing in my byte array, adding the ContentType attribute to the ByteArrayContent Headers, then using PostAsync instead of PostAsJsonAsync. This worked perfectly.

Here is the code:

public JobResponse RunInformaticaJob(JobRequest jobRequest)
    {
        try
        {
            client = new HttpClient();
            client.DefaultRequestHeaders.Clear();
            client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
            client.DefaultRequestHeaders.TryAddWithoutValidation("Content-Type", "application/json");
            client.DefaultRequestHeaders.TryAddWithoutValidation("icSessionId", icSessionId);

            string message = JSONSerializer.Serialize(jobRequest);
            message = message.Insert(1, "\"@type\": \"job\",");
            byte[] messageBytes = System.Text.Encoding.UTF8.GetBytes(message);
            var content = new ByteArrayContent(messageBytes);
            content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/json");

            var response = client.PostAsync(loggedUser.serverUrl + "/api/v2/job", content).Result;
            if (response.IsSuccessStatusCode)
            {
                return response.Content.ReadAsAsync<JobResponse>().Result;
            }
            else
            {
                var result = response.Content.ReadAsStringAsync().Result;
                Console.WriteLine(result);
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
        }
        return null;
    }

Issue resolved!