Entity Framework Core esegue seed

Uso EF Core per creare AppDBContext e AppDbContextSeed :

AppDbContextSeed

public class AppDbContextSeed
{
    private readonly AppDbContext _dbContext;
    private UserManager<AppUser> _userManager;
    private RoleManager<AppRole> _roleManager;

    public AppDbContextSeed(AppDbContext dbContext, UserManager<AppUser> userManager,
        RoleManager<AppRole> roleManager)
    {
        _dbContext = dbContext;
    }

    public async Task Seed()
    {
        ...
        await _dbContext.SaveChangesAsync();
    }
}

Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    services.AddTransient<AppDbContextSeed>();
}

Program.cs

public static void Main(string[] args)
{
    var host = BuildWebHost(args);

    using (var scope = host.Services.CreateScope())
    {
        var services = scope.ServiceProvider;

        try
        {
            var appDbContextSeed = services.GetService<AppDbContextSeed>();
            appDbContextSeed.Seed().Wait();
        }
        catch (Exception ex)
        {
            var logger = services.GetService<ILogger<Program>>();
            logger.LogError(ex, "An error occurred while seeding the database");
        }
    }

    host.Run();
}

Quando appDbContextSeed add-migration e update-database , nessun dato da appDbContextSeed viene inserito nel database. Che cosa ho fatto di sbagliato?