CustomScrollView and SliverGrid Repeating

I have a CustomScrollView that receives a future sliver, it works but the sliver keeps on repeating its elements

Here is my code in homepage

  late Future<List<DatabaseContent>> europe;

  @override
  void initState() {
    super.initState();
    europe = DatabaseHelper.instance.getDatabaseContent();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text(widget.title),
        ),
        body: CustomScrollView(
          slivers: [
            FutureBuilder(
              future: europe,
              builder: (context, snapshot) {
                if (snapshot.hasData) {
                  return EuropeGroup(data: snapshot.data!);
                } else {
                  return const LoadingSliver();
                }
              },
            )
          ],
        ));
  }

The data is passed to this widget, it displays everything correctly but keeps repeating the elements indefinitely

class EuropeGroup extends StatefulWidget {
  final List<DatabaseContent> data;
  const EuropeGroup({super.key, required this.data});
  @override
  State<EuropeGroup> createState() => _EuropeGroupState();
}

class _EuropeGroupState extends State<EuropeGroup> {
  SliverGridDelegate gridDelegate =
      const SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 2);

  int _childCount = 0;

  @override
  Widget build(BuildContext context) {
    return SliverGrid(
        delegate: SliverChildBuilderDelegate(
          childCount: widget.data.length,
          (context, index) {
            DatabaseContent _current = widget.data[index];
            return Card(
              child: Text("${_current.last_update} "
                  "${_current.geo} "
                  "${_current.time_period} "
                  "${_current.obs_value} "
                  "${_current.obs_flag} "),
            );
          },
        ),
        gridDelegate: gridDelegate);
  }
}

I tried searching google but did not found relevant info why this is happening

Use initstate to initialize the variable

void initState() {
  super.initState();
  _childCount = widget.data.length;
}

and them use in widget

SliverChildBuilderDelegate(
  childCount: _childCount,