Retrieving claim value for current logged in user - asp.net

Question

I have an ASP.Net web form application that users can register to. In the registration process, some user details are stored as claims, the MemberApproved variable is used to check the approval status of a user, it is set to "No" when the user is created, and can be changed later by admin:
var manager = Context.GetOwinContext().GetUserManager<ApplicationUserManager>();
var signInManager = Context.GetOwinContext().Get<ApplicationSignInManager>();
var user = new ApplicationUser() { UserName = Email.Text, Email = Email.Text, FirstName = FirstName.Text, LastName = LastName.Text,MemberApproved="No" };
THis is working fine and I can see the user details above added correctly in the AspNetUsers
Then I am trying to check if the user has been approved by an admin when they login, in this process, I am trying to retrieve MemberApproved value using the following code:
protected void Page_Load(object sender, EventArgs e)
{
RegisterHyperLink.NavigateUrl = "Register";
OpenAuthLogin.ReturnUrl = Request.QueryString["ReturnUrl"];
var returnUrl = HttpUtility.UrlEncode(Request.QueryString["ReturnUrl"]);
if (!String.IsNullOrEmpty(returnUrl))
{
RegisterHyperLink.NavigateUrl += "?ReturnUrl=" + returnUrl;
}
}
protected void LogIn(object sender, EventArgs e)
{
if (IsValid)
{
var manager = Context.GetOwinContext().GetUserManager<ApplicationUserManager>();
var signinManager = Context.GetOwinContext().GetUserManager<ApplicationSignInManager>();
var result = signinManager.PasswordSignIn(Email.Text, Password.Text, RememberMe.Checked, shouldLockout: false);
switch (result)
{
case SignInStatus.Success:
var claims = ClaimsPrincipal.Current.Identities.First().Claims.ToList();
string MemberApproved = claims?.FirstOrDefault(x => x.Type.Equals("MemberApproved", StringComparison.OrdinalIgnoreCase))?.Value;
if (MemberApproved == "No")
{
FailureText.Text = "User not approved yet";
ErrorMessage.Visible = true;
break;
}
else
{ IdentityHelper.RedirectToReturnUrl(Request.QueryString["ReturnUrl"], Response);
break;
}
case SignInStatus.LockedOut:
Response.Redirect("/Account/Lockout");
break;
case SignInStatus.RequiresVerification:
Response.Redirect(String.Format("/Account/TwoFactorAuthenticationSignIn?ReturnUrl={0}&RememberMe={1}",
Request.QueryString["ReturnUrl"],
RememberMe.Checked),
true);
break;
case SignInStatus.Failure:
default:
FailureText.Text = "Invalid login attempt";
ErrorMessage.Visible = true;
break;
}
}
}
}
I am however running into problems and the code above does not seem to be able to retrieve the value of "MemberApproved"
Any suggestions would be very much appreciated.