Repository: flutter
Issue: Vertical incline scrolling didn't work all the time in nested scrolling approach
Labels: framework,f: scrolling,has reproducible steps,P2,found in release: 3.10,found in release: 3.11,team-framework,triaged-framework

Hi Team, I need to provide nested scrolling support for my application. In that, I couldn't able to do vertical incline scrolling all the time. Please do the needful.

## Steps to Reproduce

1. Find the code snippets below
```dart
import 'package:flutter/material.dart';

class NestedScrollDemo extends StatefulWidget {
  NestedScrollDemo({Key? key}) : super(key: key);

  @override
  _NestedScrollDemoState createState() => _NestedScrollDemoState();
}

class _NestedScrollDemoState extends State<NestedScrollDemo> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Nested scroll demo'),
      ),
      body: SingleChildScrollView(
        scrollDirection: Axis.vertical,
        child: SingleChildScrollView(
          scrollDirection: Axis.horizontal,
          child: Column(
            children: List.generate(30, (index) => _buildRow(index)),
          ),
        ),
      ),
    );
  }
}

Widget _buildRow(int rowIndex) {
  return Row(
    children: List.generate(
      6,
      (colIndex) => Container(
        alignment: Alignment.center,
        decoration: BoxDecoration(
            border:
                Border.all(color: Colors.grey.withOpacity(0.45), width: 1.0)),
        child: Text('Row $rowIndex'),
        width: 100,
        height: 50,
      ),
    ),
  );
}

```
2. Demo video

https://user-images.githubusercontent.com/60499432/116987616-e76ef500-acec-11eb-8577-4fbee08196e0.mp4

**Expected results:** Scrolling should be worked all the time.

**Actual results:** Scrolling did not work randomly.

<details>
  <summary>Logs</summary>

```
Analyzing example...
No issues found! (ran in 19.5s)
```

```
[√] Flutter (Channel stable, 2.0.3, on Microsoft Windows [Version 10.0.18363.1440], locale en-US)
    • Flutter version 2.0.3 at C:\src\flutter
    • Framework revision 4d7946a68d (7 weeks ago), 2021-03-18 17:24:33 -0700
    • Engine revision 3459eb2436
    • Dart version 2.12.2

[√] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
    • Android SDK at C:\Users\AshokKuvaraja\AppData\Local\Android\sdk
    • Platform android-30, build-tools 30.0.3
    • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1248-b01)
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop for Windows (Visual Studio Professional 2019 16.4.5)
    • Visual Studio at C:\Program Files (x86)\Microsoft Visual Studio\2019\Professional
    • Visual Studio Professional 2019 version 16.4.29806.167
    • Windows 10 SDK version 10.0.18362.0

[√] Android Studio (version 3.3)
    • Android Studio at C:\Program Files\Android\Android Studio
    • Flutter plugin version 34.0.1
    • Dart plugin version 182.5215
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1248-b01)

[√] VS Code, 64-bit edition (version 1.55.1)
    • VS Code at C:\Program Files\Microsoft VS Code
    • Flutter extension version 3.21.0

[√] Connected device (4 available)
    • Moto G 5S (mobile)           • ZY3228D7NG    • android-arm    • Android 7.1.1 (API 25)
    • AOSP on IA Emulator (mobile) • emulator-5554 • android-x86    • Android 9 (API 28) (emulator)
    • Windows (desktop)            • windows       • windows-x64    • Microsoft Windows [Version 10.0.18363.1440]
    • Chrome (web)                 • chrome        • web-javascript • Google Chrome 90.0.4430.93

• No issues found!
```

</details>