It doesn't work with two sliverList in CustomScrollView

[jiang111]

can not scroll to the target index in this example, this example use CustomScrollView with two sliverList

import 'package:flutter/material.dart';
import 'package:scroll_to_index/scroll_to_index.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: HomePage(),
    );
  }
}

class HomePage extends StatefulWidget {
  const HomePage({Key? key}) : super(key: key);

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  List<int> first = [];
  List<int> second = [];
  int count = 20;

  @override
  void initState() {
    List.generate(count, (index) {
      first.add(count - 1 - index);
      second.add(index + count);
    });

    super.initState();
  }

  ValueKey key = const ValueKey("key");
  final controller = AutoScrollController(
    viewportBoundaryGetter: () => const Rect.fromLTRB(0, 0, 0, 0),
    axis: Axis.vertical,
  );

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: CustomScrollView(
        cacheExtent: 1,
        controller: controller,
        center: key,
        keyboardDismissBehavior: ScrollViewKeyboardDismissBehavior.onDrag,
        physics: const AlwaysScrollableScrollPhysics(),
        slivers: [
          SliverList(
            delegate: SliverChildBuilderDelegate(
              (context, index) {
                return AutoScrollTag(
                  key: ValueKey(first[index]),
                  controller: controller,
                  index: first[index],
                  child: ListTile(
                    onTap: () {
                      controller.scrollToIndex(first[index] + count, preferPosition: AutoScrollPosition.begin);
                    },
                    title: Text("${first[index]}"),
                  ),
                );
              },
              childCount: first.length,
            ),
          ),
          SliverList(
            key: key,
            delegate: SliverChildBuilderDelegate(
              (context, index) {
                return AutoScrollTag(
                  key: ValueKey(second[index]),
                  controller: controller,
                  index: second[index],
                  child: ListTile(
                    onTap: () {
                      controller.scrollToIndex(second[index] - count, preferPosition: AutoScrollPosition.begin);
                    },
                    title: Text("${second[index]}"),
                  ),
                );
              },
              childCount: second.length,
            ),
          ),
        ],
      ),
    );
  }
}

[eugene9918]

Give false value "primary" of custom scrollview