Blazor application doesn't load the page when hosted in IIS

Im trying to deploy my Blazor WebAssembly application (.NET 5.0) to an IIS server. When I load the page I get a HTTP Error 404. With this there is also an API which I use Swagger for. I can load Swagger and also query the API via Postman, its just the Blazor UI doesn't load. WHat reasons could cause this please?

I have installed the .NET Core Runtime Hosting Bundle on the server. There are no errors appearing in the console index.html is present in wwwroot folder

If I publish the Blazor application on its own, then the page loads (with errors as the API has not been uploaded). When I publish from the Web API application then the API works but the Blazor doesn't.

Blazor Application

.NET 5.0

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=".\AppName.Server.dll" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" />
</system.webServer>

Program.cs -

 public static async Task Main(string[] args)
    {
        var builder = WebAssemblyHostBuilder.CreateDefault(args);
        builder.Services.AddScoped(sp => new HttpClient { BaseAddress = new Uri(builder.HostEnvironment.BaseAddress) });


        builder.RootComponents.Add<App>("app");



        builder.Services.AddBlazoredLocalStorage();
        builder.Services.AddAuthorizationCore();
        builder.Services.AddScoped<AuthenticationStateProvider, ApiAuthenticationStateProvider>();
        builder.Services.AddHttpClient<IAuthService, AuthService>();

        builder.Services.AddScoped<DialogService>();
        builder.Services.AddScoped<NotificationService>();
        builder.Services.AddScoped<TooltipService>();
        builder.Services.AddScoped<ContextMenuService>();
        builder.Services.AddScoped<ClipboardService>();

        await builder.Build().RunAsync();
    }

Web API -

.NET 5.0

Startup.cs -

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container.
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddServerSideBlazor();
        services.AddMvc().AddNewtonsoftJson();

        services.AddSwaggerGen(c =>
        {
            c.SwaggerDoc("v1", new OpenApiInfo { Title = "AppTitle API", Version = "v1" });
        });

        services.AddDbContext<ApplicationDbContext>(options =>
            options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")).EnableDetailedErrors());

        services.AddDefaultIdentity<IdentityUser>(options => options.Lockout.AllowedForNewUsers = false)
            .AddRoles<IdentityRole>()
            .AddEntityFrameworkStores<ApplicationDbContext>();

        var tokenValidationParameters = new TokenValidationParameters
        {
            ValidateIssuer = true,
            ValidateAudience = true,
            ValidateLifetime = true,
            ValidateIssuerSigningKey = true,
            ValidIssuer = Configuration["JwtIssuer"],
            ValidAudience = Configuration["JwtAudience"],
            IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["JwtSecurityKey"]))
        };

        services.AddSingleton(tokenValidationParameters);

        services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
                .AddJwtBearer(options =>
                {
                    options.SaveToken = true;
                    options.TokenValidationParameters = tokenValidationParameters;
                });

        services.AddResponseCompression(opts =>
        {
            opts.MimeTypes = ResponseCompressionDefaults.MimeTypes.Concat(
                new[] { "application/octet-stream" });
        });

        services.AddCors(options =>
        {
            options.AddDefaultPolicy(
            builder =>
            {
                builder.WithOrigins("https://localhost:44326",
                                        "https://localhost:44345")
                .AllowAnyHeader()
                .AllowAnyMethod()
                .AllowCredentials();
            });
        });
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        app.UseDeveloperExceptionPage();

        app.UseResponseCompression();

        app.UseStaticFiles(new StaticFileOptions()
        {
            FileProvider = new PhysicalFileProvider(
        Path.Combine(Directory.GetCurrentDirectory(), @"upload")),
            RequestPath = new PathString("/upload") 
        });

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }

        app.UseRouting();

        app.UseCors();

        app.UseAuthentication();
        app.UseAuthorization();

            app.UseSwagger();
            app.UseSwaggerUI(c => c.SwaggerEndpoint("v1/swagger.json", "AppTitle API"));

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

        
    }
}

UPDATE

Failed Request Trace in IIS

The only error produced in FRT is -

102. -NOTIFY_MODULE_START

ModuleName AspNetCoreModuleV2

Notification EXECUTE_REQUEST_HANDLER

fIsPostNotification false

750 ms

Warning 103. -MODULE_SET_RESPONSE_ERROR_STATUS

ModuleName AspNetCoreModuleV2

Notification EXECUTE_REQUEST_HANDLER

HttpStatus 404

HttpReason Not Found

HttpSubStatus 0

ErrorCode The operation completed successfully. (0x0)

ConfigExceptionInfo