I am having an issue with my ASP.NET Core 8 Web API after deployment to a production site in IIS. In this case I have structured so that it is an application under an existing site (e.g. admin.example.com -> api). When navigating / posting to the endpoint I receive a http 404 error. When I dotnet the .dll file, I get this error:

An attempt was made to access a socket in a way forbidden by its access permissions (line 95)

My program.cs (app.run is @ line 95 in full code):

using Newtonsoft.Json.Linq;
using Models;
using System.Net;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Data.SqlClient;
using Microsoft.Extensions.Configuration;

var builder = WebApplication.CreateBuilder(args);

builder.WebHost.ConfigureKestrel((context, options) =>
{
    options.Configure(context.Configuration.GetSection("Kestrel"));
});

builder.Services.AddControllers()
.AddNewtonsoftJson();

builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();
app.UseRouting();
app.UseAuthorization();

app.MapPost($"api/receivejson", async (HttpContext context) =>
{
    // Do shit (no 404s)
});

app.MapControllers();

app.Run();

And my appsettings.json file:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "Kestrel": {
    "Endpoints": {
      "HttpsInlineCertFile": {
        "Url": "https://admin.example.com",
        "Certificate": {
          "Path": "C:\Path\Here",
          "Password": ""
        }
      }
    }
  },
  "AllowedHosts": "*"
}

Web.config:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <location path="." inheritInChildApplications="false">
    <system.webServer>
      <handlers>
        <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModuleV2" 
resourceType="Unspecified" />
      </handlers>
      <aspNetCore processPath="dotnet" arguments=".MyApp.dll" 
stdoutLogEnabled="false" stdoutLogFile=".logsstdout" hostingModel="inprocess" />
    </system.webServer>
  </location>
</configuration>
<!--ProjectGuid: GuidHere -->

Any help would be much appreciated – I’ve looked far and wide and have had no luck thus far.