List of widgets safe it's state when use clear method

I have a StatelessWidget and I am using Provider. In my provider class I have a list of widget:

List<Widget> gridList= [];

When my provider is started, I call the init method. In my method, I fill gridList by list of widget:

  void listCheck(BuildContext context) {
    receiptFilterTypes.forEach((item) {
      gridList.add(
        Container(
          key: UniqueKey(),
          width: MediaQuery.of(context).size.width * 0.45,
          child: MyCheckBox(
            margin: EdgeInsets.all(0),
            title: item.name,
            selected: filter?.types?.contains(item) ?? false,
            onChanged: (value) {
              if (!(filter?.types?.contains(item) ?? false)) {
                filter.types.add(item);
              } else {
                filter.types.remove(item);
              }
            },
          ),
        ),
      );
    });
    notifyListeners();
  }

In my page, I have a list of MyCheckBox. Now, I want, when user taps on Select_All button, to check all MyCheckBox. So, I wrote this method:

  void selectAll(BuildContext context) {
    filter.types.clear();
    receiptFilterTypes.forEach((item) {
      filter.types.add(item);
    });
    gridList.clear();
    listCheck(context);
    notifyListeners();}

The problem is here, when gridList is cleared and I made again list of widget listCheck(context); after notifyListeners the state of

MyCheckBox(
    margin: EdgeInsets.all(0),
    title: item.name,
    selected: filter?.types?.contains(item) ?? false,

Not changed. Although selected is true but user still see a checkbox not selected.

I fixed the problem by creating a new instance of gridList:

  void listCheck(BuildContext context) {
    gridList = []; //---- I added this
    receiptFilterTypes.forEach((item) {
      gridList.add(
        Container(
          key: UniqueKey(),
          width: MediaQuery.of(context).size.width * 0.45,
          child: MyCheckBox(
            margin: EdgeInsets.all(0),
            title: item.name,
            selected: filter?.types?.contains(item) ?? false,
            onChanged: (value) {
              if (!(filter?.types?.contains(item) ?? false)) {
                filter.types.add(item);
              } else {
                filter.types.remove(item);
              }
            },
          ),
        ),
      );
    });
    notifyListeners();
  }

Why do I have to create a new instance of gridList, and why does gridList.clear() not work?

I am using of my list in main page like this:

   Consumer<MyProvider>(
        builder: (context, model, child) 
      {
          return GridView.count(
            shrinkWrap: true,
            physics: NeverScrollableScrollPhysics(),
            crossAxisCount: 2,
            mainAxisSpacing: 3,
            crossAxisSpacing: 5,
            childAspectRatio: 3.5,
            children: model.gridList, //--> It's filled with new values but not working
          ),