OWIN 2FA Sign In Succeeded by User not Authenticated

Question

I'm trying to implement a custom Two Factor Sign in for a private website. (Previously was set for specific IPs, but client wants to view whenever and whatever device).

So, I've created a custom SMS & Email Provider, Token Provider etc - All that appears to work fine. The Token is saved in the DB (UserTokens) and I can call "TwoFactorSignInAsync" successfully and the result == "Succeeded". Now here lies my problem, desire the user being logged in. Subsequent requests do not show the user as authenticated, the "User.Identity.IsAuthenticated" property is always false. I feel like I must have missed a step but can't see to get around it.

Added into my Identity in start up

.AddTokenProvider<TwoFactorTokenProvider<UserEntity>>("OGSecurityCode");

My Class

public class TwoFactorTokenProvider<UserEntity> : DataProtectorTokenProvider<UserEntity> where UserEntity : class
{
    public TwoFactorTokenProvider(IDataProtectionProvider dataProtectionProvider,
        IOptions<TwoFactorTokenProviderOptions> options,
        ILogger<DataProtectorTokenProvider<UserEntity>> logger)
        : base(dataProtectionProvider, options, logger)
    {
        base.Options.Name = "OGSecurityCode";
    }

    public override Task<string> GenerateAsync(string purpose, UserManager<UserEntity> manager, UserEntity user)
    {
        Task<string> t = (Task<string>)Task.Run(async () =>
        {
            Random generator = new Random();
            string theCode = generator.Next(100000, 999999).ToString("D6");

            await manager.SetAuthenticationTokenAsync(user, manager.Options.Tokens.AuthenticatorTokenProvider, purpose, theCode);

            return theCode;
        });
        return t;
    }
    public override Task<bool> CanGenerateTwoFactorTokenAsync(UserManager<UserEntity> manager, UserEntity user)
    {
        return Task.Run<bool>(() => { return true; });
    }
    public override async Task<bool> ValidateAsync(string purpose, string token, UserManager<UserEntity> manager, UserEntity user)
    {
        string theCode = await manager.GetAuthenticationTokenAsync(user, manager.Options.Tokens.AuthenticatorTokenProvider, purpose);
        return (theCode.Equals(token, StringComparison.OrdinalIgnoreCase));
    }
}

Generating code

 securityKey = await _userManager.GenerateTwoFactorTokenAsync(user, "OGSecurityCode");

Sign in with code

var tfresult = await _signInManager.TwoFactorSignInAsync("OGSecurityCode", securityKey, model.RememberMe, model.RememberMachine);
                        if (tfresult.Succeeded)
                        {

//Gets here successfully }