onPaymentResult callback always returning pending status as pending and not redirecting to webview.

[Samriddhi98]

Describe the bug
I am using the sandbox environment to test khalti payment integration. The code seems to have worked for the first couple of times but afterwards the payment status returns 'pending' and the webview is not loading.

To Reproduce
I have used bloc to initialize khalti like this:

class KhaltiBloc extends Bloc<KhaltiEvent, KhaltiState> {
  KhaltiBloc() : super(KhaltiInitial()) {
    on<InitializeKhalti>(_initializeKhalti);
  }

  PaymentResult? paymentResult;

  FutureOr<void> _initializeKhalti(
      InitializeKhalti event, Emitter<KhaltiState> emit) async {
    emit(KhaltiLoading());
    final context = event.context;
    final payConfig = KhaltiPayConfig(
      publicKey:
          event.publicKey, // This is a dummy public key for example purpose
      pidx: event.pidx,
      environment: Environment.test,
    );
    try {
      final khalti = await Khalti.init(
        enableDebugging: true,
        payConfig: payConfig,
        onPaymentResult: (paymentResult, khalti) {
          log('--pay info ------');
          log(paymentResult.toString());
          paymentResult = paymentResult;
          khalti.close(context);
        },
        onMessage: (
          khalti, {
          description,
          statusCode,
          event,
          needsPaymentConfirmation,
        }) async {
          log(
            'Description: $description, Status Code: $statusCode, Event: $event, NeedsPaymentConfirmation: $needsPaymentConfirmation',
          );
          khalti.close(context);
        },
        onReturn: () {
          log('Successfully redirected to return_url.');
        },
      );
      emit(KhaltiInitalizeSuccess(khalti: khalti));
    } catch (e) {
      emit(KhaltiInitializeError());
    }
  }
}

Note

the test credentials I used the first few times were:
Test Khalti ID 9800000005
Test MPIN 1111
Test OTP 987654