Repository: flutter
Issue: [A11y][iOS] Implicit scrolling doesn't work with two scrollables on the screen
Labels: platform-ios,framework,a: accessibility,f: scrolling,has reproducible steps,P2,found in release: 3.7,found in release: 3.9,team-ios,triaged-ios

Hi! This issue is not isolated to the exact case I describe here, it also happens when I have scrollable next to each other (not nested), with builders, or with explicit children widget list.

This is also very flaky, sometimes it lets me swipe to items outside of the viewport, sometimes it does not.

This breaks carousels and different screens using scroll in our app. Not every user using a screen reader will know that some additional content is available once they scroll the app using three-finger swipe gesture on VoiceOver. They will stop once they hear end of nodes sound when one-finger swiping right.

#### Reproduction steps
I reproduced it on iPhone 13 Pro but it's probably also on Android.

1. Run app with enabled VoiceOver
2. Swipe right a few times to get to the horizontal list items
3. Do a three finger swipe down to scroll the vertical list once
4. Either tap on item 4 or swipe-right until you get to it
5. You cannot swipe-right to item 5 and next ones. You also can't swipe-left back to item 1 or 0.

#### Code
```dart
import 'package:flutter/material.dart';

void main() {
  runApp(const App());
}

class App extends StatelessWidget {
  const App({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: MainScreen(),
    );
  }
}

class MainScreen extends StatelessWidget {
  const MainScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: ListView.builder(
        itemCount: 30,
        itemBuilder: (context, i) => i == 2
            ? SizedBox(
                height: 100,
                child: ListView.builder(
                  scrollDirection: Axis.horizontal,
                  itemCount: 15,
                  itemBuilder: (context, i) => Column(
                    children: [
                      const FlutterLogo(),
                      Text('Item $i'),
                    ],
                  ),
                ),
              )
            : ListTile(
                title: Text('Item $i'),
                subtitle: const Placeholder(),
              ),
      ),
    );
  }
}

```

Video with reproduction steps

<details>

https://user-images.githubusercontent.com/4085280/228879734-e7d0fdab-7c4f-4dd2-8b3a-a62482af093b.MP4

</details>

Some other flakiness of swiping right/left and sometimes getting the end of content sound

<details>

https://user-images.githubusercontent.com/4085280/228880205-2f4c99af-086a-4a5c-912a-9fbe7db8ae9e.MP4

</details>

```
[!] Flutter (Channel stable, 3.7.6, on macOS 13.1 22C65 darwin-arm64, locale en-PL)
    • Flutter version 3.7.6 on channel stable at /Users/albert/fvm/versions/3.7.6
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 12cb4eb7a0 (4 weeks ago), 2023-03-01 10:29:26 -0800
    • Engine revision ada363ee93
    • Dart version 2.19.3
    • DevTools version 2.20.1

[✓] Xcode - develop for iOS and macOS (Xcode 14.2)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 14C18
    • CocoaPods version 1.11.3
[✓] Connected device (4 available)
    • Albert’s iPhone (mobile)    • 00008110-xxx • ios            • iOS 16.3.1 20D67
```