Xamarin iOS Oidc downloads webpage after login - ios

Question

I have an app that uses Oidc to login. This works fine in most cases. But there is one iphone 8+ running iOS 15.6.1 that keeps downloading the return url from the login request.
i use Xamarin forms v 5.0.0.2515, Xamarin.Essentials 1.7.3, Xamarin.CommunityToolkit 2.0.5
IdentityModel.OidcClient 3.1.2
The problem is that it works on all other devices and i can't replicate it in a dev environment.
public class WebauthenticatorBrowser : IBrowser
{
private readonly string callbackUrl;
public WebauthenticatorBrowser(string? callbackUrl = null)
{
this.callbackUrl = callbackUrl;
}
public async Task<BrowserResult> InvokeAsync(BrowserOptions options, CancellationToken cancellationToken = default)
{
try
{
var callBack = string.IsNullOrWhiteSpace(callbackUrl) ? options.EndUrl : callbackUrl;
var authResult = await WebAuthenticator.AuthenticateAsync(new WebAuthenticatorOptions
{
Url = new Uri(options.StartUrl),
CallbackUrl = new Uri(callBack),
PrefersEphemeralWebBrowserSession = false
});
var authorizeResponse = ToRawIdentityUrl(options.EndUrl, authResult);
return new BrowserResult()
{
Response = authorizeResponse
};
}
catch (Exception ex)
{
return new BrowserResult()
{
Error = ex.Message
};
}
}
private string ToRawIdentityUrl(string redirectUrl, WebAuthenticatorResult result)
{
IEnumerable<string> parameters = result.Properties.Select(x => $"{x.Key}={x.Value}");
var values = string.Join("&", parameters);
return $"{redirectUrl}#{values}" ;
}
}
In my oidc class where i create my client
private async Task createOidcClient() {
document = await httpClient.GetDiscoveryDocumentAsync(idsUrl);
if (document.IsError) {
alertPresenter.Alert("Connection issue", "please try again");
return;
}
var options = new OidcClientOptions {
Authority = document.Issuer,
ClientId = "---clientID-",
Scope = "-- all the scopes --",
RedirectUri = "-- callback url--",
PostLogoutRedirectUri = " -- callback url--",
Browser = new WebauthenticatorBrowser(),
ResponseMode = OidcClientOptions.AuthorizeResponseMode.Redirect
};
client = new OidcClient(options);
}
the login call in the OicdClass
public async Task<LoginResult> Login() {
await createOidcClient();
var result = await client.LoginAsync(new LoginRequest());
if (result.IsError) return result;
setAuthHeader(result.AccessToken);
await accessTokenUpdater.SetAllTokens(result.AccessToken, result.RefreshToken, result.IdentityToken);
return result;
}