Azure AD B2C - HTTP Error 400 - Request Header field is too long

I am using Microsoft.Idendity.Client(V4.0.0) library along with Xamarin for login to Azure AD B2C account.

Previously I was using external browse(chrome) for opening the login window. And yesterday I changed the code like given below.

var result = await _authenticationClient.AcquireTokenInteractive(_settings.Scopes)
                    .WithParentActivityOrWindow(ParentActivityOrWindow)
                    .WithPrompt(Prompt.ForceLogin)
                    .WithUseEmbeddedWebView(true)
                    .ExecuteAsync();

I have changed the behavior to open the embedded browser for login by adding the .WithUseEmbeddedWebView(true) configuration.

After changing this, I am getting an error page(intermittently) saying that “Bad Request - Header Field too long”

HTTP Error 400 - Request Header field is too long.

Attaching the error image for your reference.

Could you please let me know why this issue is coming and how I can resolve it. Do I need to consider for something else, in case if I am using EmbeddedWebView.

Also I have noticed that It is not coming every-time. Seems like something weird happen with my code.

Please help.

[rkshnair]

I have added the below code when the user try for re-login and everything works fine for me.

 public Task ClearCookiesAsync()
        {
            var context = Android.App.Application.Context;

            if (Build.VERSION.SdkInt >= BuildVersionCodes.LollipopMr1)
            {
                System.Diagnostics.Debug.WriteLine("Clearing cookies for API >= LollipopMr1");
                CookieManager.Instance.RemoveAllCookies(null);
                CookieManager.Instance.Flush();
            }
            else
            {
                System.Diagnostics.Debug.WriteLine("Clearing cookies for API < LollipopMr1");
#pragma warning disable CS0618 // Type or member is obsolete
                var cookieSyncMngr = CookieSyncManager.CreateInstance(context);
#pragma warning restore CS0618 // Type or member is obsolete
                cookieSyncMngr.StartSync();
                var cookieManager = CookieManager.Instance;
                cookieManager.RemoveAllCookie();
                cookieManager.RemoveSessionCookie();
                cookieSyncMngr.StopSync();
                cookieSyncMngr.Sync();
            }

            return Task.FromResult(true);
        }

[bgavrilMS]

Thanks for following up @rkshnair !