WebApi POST request gets handled by GET - post

Question

I'm using RestSharp to consume my WebApi. Here is the relevant code:
var insertRequest = new RestRequest("MappedSystem", Method.POST);
insertRequest.AddBody(new MappedSystemCreateModel
{
MappedSystemDetails = new MappedSystemCreateModel.Details
{
SystemName = "TestName",
SystemVersion = "TV"
}
});
var response = RestClient.Execute(insertRequest);
But when I debug my WebApi it hits the Get() method:
public class MappedSystemController : ApiController
{
private readonly IMappedSystemService _mappedSystemService;
public MappedSystemController(IMappedSystemService mappedSystemService)
{
_mappedSystemService = mappedSystemService;
}
public MappedSystemViewModel[] Get()
{
=> return _mappedSystemService.Get();
}
public MappedSystemViewModel Get(Guid id)
{
return _mappedSystemService.Get(id);
}
[HttpPost]
public MappedSystemViewModel Post([FromBody]MappedSystemCreateModel model)
{
return _mappedSystemService.Post(model);
}
}
I think there must be something wrong with my routeConfig, but I don't know at this point:
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}/{id2}/",
defaults: new { id = RouteParameter.Optional, id2 = RouteParameter.Optional }
);

Answer 1

There was a Post route handler interceptor checking to see if I had correctly added a trailing '/'. Since I hadn't it responded with a 301 and redirected. Somehow/somewhere in the RedirectPermanently() the Verb was getting lost. The answer was to originally make the request with the trailing '/'. But of course this does shed light on the error found in the redirect.
Also, I needed this following code on the request or the body wouldn't deserialize:
insertRequest.RequestFormat = DataFormat.Json;