Flutter setState not updating a particular widget

Can you share the full code.. like the part where you have declared variables like labels and conditions. You need to make sure that these variables are not final firstly and that these are using the late keyword or something like List? labels. If there's any other problem kindly share the whole code of this stateful class

**EDIT

So I tried this given Chip Widget with custom data and it is working properly.. Meaning the items that i am adding on pressed are being added to the new list. Take a look and try out the few changes and see if that works for you

class _MyHomePageState extends State<MyHomePage> {
static List<Animal> _animals = [
Animal(id: 1, name: "Lion"),
Animal(id: 2, name: "Flamingo"),
Animal(id: 3, name: "Hippo"),
Animal(id: 4, name: "Horse"),
Animal(id: 5, name: "Tiger"),
Animal(id: 6, name: "Penguin"),
Animal(id: 7, name: "Spider"),
Animal(id: 8, name: "Snake"),
Animal(id: 9, name: "Bear"),
Animal(id: 10, name: "Beaver"),
Animal(id: 11, name: "Cat"),
Animal(id: 12, name: "Fish"),
Animal(id: 13, name: "Rabbit"),
];
dynamic _items = _animals
  .map((animal) => MultiSelectItem<Animal>(animal, animal.name))
  .toList();
@override
Widget build(BuildContext context) {
return new Scaffold(
  backgroundColor: Colors.white,
  appBar: new AppBar(
    title: new Text('Hello'),
  ),
  body: ListView(
    scrollDirection: Axis.vertical,
    physics: NeverScrollableScrollPhysics(),
    children: [
      Container(
        child: MultiSelectChipField(
          scroll: false,
          decoration: BoxDecoration(
            border: Border.all(color: Colors.transparent, width: 1.8),
          ),
          showHeader: false,
          selectedTextStyle: TextStyle(
            fontSize: 12.5,
            height: 1.8,
            fontWeight: FontWeight.w400,
            color: Colors.blue,
          ),
          chipShape: RoundedRectangleBorder(
            borderRadius: BorderRadius.all(
              Radius.circular(12),
            ),
          ),
          selectedChipColor: Colors.green,
          chipColor: Colors.yellow,
          textStyle: TextStyle(
            fontSize: 12.5,
            height: 1.8,
            fontWeight: FontWeight.w400,
            color: Colors.black,
          ),
          items: _items,
          onTap: (value) {
            ///add symptoms to list
            print(value);
          },
        ),
      ),
      ElevatedButton(
          onPressed: () {
            _items.add(MultiSelectItem<Animal>(
                Animal(id: 27, name: 'name'), 'new'));
            setState(() {});
          },
          child: Text('Add'))
    ],
  ),
  );
 }
}

 class Animal {
  final int id;
  final String name;

Animal({
required this.id,
required this.name,
});

}