ChangeNotifierProxyProvider Problem while authentication - flutter

Question

Authentication class
class Authentication with ChangeNotifier{
String _authToken='';
String _userId= '';
String get authToken{
return _authToken;
}
String get userId{
return _userId;
}
bool get isTokenValid{
print(authToken);
return _authToken.isNotEmpty;
}
Future<void> signIn(Map<String,Object> payload) async {
final url = Uri.parse("http://10.0.2.2:9090/api/v1/auth/register");
try{
final response= await http.post(url,
headers: {'Content-Type': 'application/json'},
body: json.encode(
{
'firstName': payload['firstName'],
'email': payload['email'],
'password': payload['password'],
}
),);
final responseData = json.decode(response.body);
_authToken = responseData['token'];
_userId = responseData['userId'].toString();
}catch(exception){
rethrow;
}
notifyListeners();
}
Future<void> logIn(Map<String,Object> payload) async {
final url = Uri.parse("http://10.0.2.2:9090/api/v1/auth/authenticate");
try{
final response= await http.post(url,
headers: {'Content-Type': 'application/json'},
body: json.encode(
{
'email': payload['email'],
'password': payload['password'],
}
),);
final responseData = json.decode(response.body);
_authToken = responseData['token'];
_userId = responseData['userId'].toString();;
print("LogIn");
}catch(exception){
rethrow;
}
notifyListeners();
}
}
Main.dart
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
ChangeNotifierProvider.value(
value: Authentication()),
ChangeNotifierProxyProvider<Authentication,CreditData>(
create: (_) => CreditData('', [],''),
update: (ctx, authentication, prevCreditData) =>
CreditData(
authentication.authToken,prevCreditData == null ? [] : prevCreditData.data,
authentication.userId
),
),
],
child: Consumer<Authentication>(
builder: (ctx, auth, _) => MaterialApp(
title: "Money Management",
debugShowCheckedModeBanner: false,
home: auth.isTokenValid ? const Home():const AuthenticationScreen(),
routes: {
Home.routeName: (ctx) => const Home(),
Debit.routeName: (ctx) => const Debit()
},
),
)
);
}
}
When I use ChangeNotifierProxyProvider in-order to send the authToken and userId generated from Authentication class my springboot api is behaving infinte loop while the request was only once.
This is the way the server is repeating the request itself when I tried to debug threadpoolExecutor was in ifinite loop and I got no idea what to do (https://i.stack.imgur.com/vI4T3.png)
But when I use postman or ChangeNotifierProvider (not ChangeNotifierProxyProvider) i'm not getting this problem as you can see down
(https://i.stack.imgur.com/qRNj3.png)
Can someone please rectify the problem and mention why is it so happening?