ASP.NET Core 3.1: IdentityServer4: ASP.NET Identity: Invalid Username or Password - identityserver4

Question

I have an ASP.Net Core 3.1 web application with IdentityServer4 and ASP.Net Identity implemented. I have configured IdentityServer4 to use Sql Server and I am able to seed an admin user into the sql server's AspNetUsers table. All this works fine. When I run my application, IdentityServer4's home page(QuickUI) is shown. When I try to see the claims for my current session, I'm prompted with a login screen. I try using the seeded admin user and password and it keeps telling me it's an invalid username or password.
Startup.cs
public void ConfigureServices(IServiceCollection services)
{
services.AddControllersWithViews();
var connectionString = Configuration.GetConnectionString("IdentityServerDatabase");
var migrationAssembly = typeof(Startup).GetTypeInfo().Assembly.GetName().Name;
services.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(connectionString));
services.AddIdentity<ApplicationUser, IdentityRole>()
.AddEntityFrameworkStores<ApplicationDbContext>()
.AddDefaultTokenProviders();
services.AddIdentityServer()
.AddDeveloperSigningCredential()
.AddAspNetIdentity<ApplicationUser>()
.AddConfigurationStore(options =>
{
options.ConfigureDbContext = b => b.UseSqlServer(connectionString, sql => sql.MigrationsAssembly(migrationAssembly));
})
.AddOperationalStore(options =>
{
options.ConfigureDbContext = b => b.UseSqlServer(connectionString, sql => sql.MigrationsAssembly(migrationAssembly));
});
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ApplicationDbContext context)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
app.UseExceptionHandler("/Error");
app.UseHsts();
}
context.Database.Migrate(); //seed an admin user
DatabaseInitializer.PopulateIdentityServer(app); //this just adds clients and their scopes to the IDS4 tables
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
});
app.UseIdentityServer();
}
ApplicationDbContext.cs
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
: base(options)
{
}
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
this.SeedSuperUser(builder);
}
private void SeedSuperUser(ModelBuilder builder)
{
string ADMIN_ID = "02174cf0–9412–4cfe-afbf-59f706d72cf6";
string ROLE_ID = "341743f0-asd2–42de-afbf-59kmkkmk72cf6";
//seed admin role
builder.Entity<IdentityRole>().HasData(new IdentityRole
{
Name = "SuperAdmin",
NormalizedName = "SUPERADMIN",
Id = ROLE_ID,
ConcurrencyStamp = ROLE_ID
});
//create user
var appUser = new ApplicationUser
{
Id = ADMIN_ID,
Email = "someemail",
EmailConfirmed = true,
UserName = "someemail",
NormalizedUserName = "someemail",
LockoutEnabled = false, NormalizedEmail = "someemail"
};
//set user password
PasswordHasher<ApplicationUser> ph = new PasswordHasher<ApplicationUser>();
appUser.PasswordHash = ph.HashPassword(appUser, "somepassword");
//seed user
builder.Entity<ApplicationUser>().HasData(appUser);
//set user role to admin
builder.Entity<IdentityUserRole<string>>().HasData(new IdentityUserRole<string>
{
RoleId = ROLE_ID,
UserId = ADMIN_ID
});
}
}
I'm not sure where the issue is; the seeded user is in the AspNetUsers table.