Flutter – boolean value of a static field not changing accordingly depending on a condition in another class

i have a method that changes a static boolean variable that i want to use to conditionally display a button widget, the value is set to true if a condition is met else it is set to false, when i print the value of the variable inside the method it displays the expected boolean value, but the problem is when i call that boolean variable from another class it doesnt print out the expected value even if the condition is met, sometimes it will still print out true even when the condition is not met, and vice versa

I created the method here

class GetBool {
//THIS IS THE VARIABLE I WANT TO BE CHANGING ITS VALUE
  static bool? isAdded;
}

void getBool(String model) async {
    print("function ran");
    User? user = FirebaseAuth.instance.currentUser;
    DocumentSnapshot<Map<String, dynamic>> document = await FirebaseFirestore
        .instance
        .collection("Cart")
        .doc(user!.uid)
        .get();

    DocumentReference docRef =
        FirebaseFirestore.instance.collection("Cart").doc(user.uid);
    List list = [];
    for (var doc in document.data()!['cart'] as Iterable) {
      list.add(doc['model']);
      print("model says before condition $model");
      print("list is $list");

      if (list.contains(model)) {
        GetBool.isAdded = true;
        print("this item exist");
        print(GetBool.isAdded);
      } else {
        GetBool.isAdded = false;
        print("this item doesnt exist");
        print(GetBool.isAdded);
      }
    }
  }

this is where i call the method

class WatchTile extends StatefulWidget {
  final Watch? watch;
  const WatchTile({this.watch, super.key});

  @override
  State<WatchTile> createState() => _WatchTileState();
}

class _WatchTileState extends State<WatchTile> {
  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: () {
        Navigator.pushNamed(
          context,
          "/watch_details",
          arguments: widget.watch,
        );
//I CALL THE METHOD HERE WHEN I NAVIGATE TO watch_details.dart
        DatabaseService().getBool(widget.watch!.model!);
      },
      child: Container(
        decoration: BoxDecoration(
          border: Border.all(color: Colors.black),
        ),
        child: Column(
          children: <Widget>[
            Container(
              height: 200,
              decoration: BoxDecoration(
                  image: DecorationImage(
                      image: NetworkImage(widget.watch!.image!),
                      fit: BoxFit.cover)),
            ),
            Container(
              padding: const EdgeInsets.only(left: 4.0),
              width: double.maxFinite,
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Text(
                    widget.watch!.brand!,
                    style: const TextStyle(color: Colors.grey),
                  ),
                  Text(widget.watch!.model!),
                  Text('$${widget.watch!.price!}'),
                ],
              ),
            )
          ],
        ),
      ),
    );
  }
}

watch_details.dart

final FirebaseAuth auth = FirebaseAuth.instance;
User? user = auth.currentUser;

class WatchDetail extends StatefulWidget {
  const WatchDetail({super.key});

  @override
  State<WatchDetail> createState() => _WatchDetailState();
}

class _WatchDetailState extends State<WatchDetail> {
  final DatabaseService _database = DatabaseService();

  int itemQuantity = 1;
  @override
  Widget build(BuildContext context) {
    print("getbool says ${GetBool.isAdded}");

    final watch = ModalRoute.of(context)?.settings.arguments as Watch;
   

    print("route args is ${watch.brand}");
    return Scaffold(
      appBar: AppBar(
        title: Text(watch.brand!),
      ),
      body: Column(
        children: <Widget>[
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Container(
//THIS IS WHERE I WANT TO CONDITIONALLY DISPLAY A WIDGET
                child: GetBool.isAdded == false
                    ? ElevatedButton(
                        style: ButtonStyle(),
                        onPressed: () async {
                          await _database.addToCart(watch.model!, watch.brand!,
                              itemQuantity, int.parse(watch.price!));
                        },
                        child: Text("Add To Cart"),
                      )
                    : ElevatedButton(
                        onPressed: () {}, child: Text("Added To Cart")),
              ),
              
            ],
          )
        ],
      ),
    );
  }
}