Repository: flutter
Issue: [webview_flutter] Multiple inputs in position: fixed elements freeze
Labels: c: regression,platform-ios,p: webview,package,has reproducible steps,P2,team-ios,triaged-ios,fyi-text-input,found in release: 3.24,found in release: 3.26

### Steps to reproduce

1. Run the code sample on an iPhone 16 Pro with iOS 18 (Simulator works too)
2. Click "Continue" on the alert that the page is user-created
3. Click the first input element
4. Click the second input element
5. Click the third input element

### Expected results

The inputs work as normal:
- Should show a cursor
- Should be clickable
- Should allow text input

### Actual results

The second input doesn't show a cursor and the third input field can't be selected at all when trying to select one after the other.

### Code sample

<details open><summary>Code sample</summary>

```dart
import 'package:flutter/material.dart';
import 'package:webview_flutter/webview_flutter.dart';

void main() => runApp(const MaterialApp(home: WebViewExample()));

class WebViewExample extends StatefulWidget {
  const WebViewExample({super.key});

  @override
  State<WebViewExample> createState() => _WebViewExampleState();
}

class _WebViewExampleState extends State<WebViewExample> {
  late final WebViewController controller;

  @override
  void initState() {
    super.initState();
    
    controller = WebViewController()
      ..setJavaScriptMode(JavaScriptMode.unrestricted)
      ..setBackgroundColor(const Color(0x00ff0000))
      ..setOnConsoleMessage((JavaScriptConsoleMessage message) {
        print("[${message.level.name}] ${message.message}");
      })
      ..setNavigationDelegate(
        NavigationDelegate(
          onNavigationRequest: (NavigationRequest request) {
            print('NavigationRequest: ${request.url}');

            return NavigationDecision.navigate;
          },
        ),
      )
      ..loadRequest(Uri.parse('https://webtoapp.w3spaces.com/pos-fixed-inputs.html'));
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Flutter Simple Example')),
      body: WebViewWidget(controller: controller),
    );
  }
}
```

If you don't want to use the w3schools test page, this is the full HTML:
```html
<!DOCTYPE html>
<html lang="en">
	<head>
		<meta charset="UTF-8">
		<meta name="viewport" content="width=device-width, initial-scale=1.0">	
	</head>
	<body>
		<div style="position: fixed;">
			<input type="text">
			<input type="text">
			<input type="text">
		</div>
	</body>
</html>

```
</details>


### Screenshots or Video

<details open>
<summary>Screenshots / Video demonstration</summary>

Here's a video of how it should look **when it works correctly**. This was tested with a WKWebview, not webview_flutter, to show that the issue lies in the webview_flutter package.

https://github.com/user-attachments/assets/f8ddba04-68e6-4b79-8a83-0bbd03e867b1


</details>


### Logs

<details open><summary>Logs</summary>

[run.txt](https://github.com/user-attachments/files/17266340/run.txt)

</details>


### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
[✓] Flutter (Channel stable, 3.24.3, on macOS 15.0 24A335 darwin-x64, locale en-US)
    • Flutter version 3.24.3 on channel stable at /Users/administrator/development/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 2663184aa7 (3 weeks ago), 2024-09-11 16:27:48 -0500
    • Engine revision 36335019a8
    • Dart version 3.5.3
    • DevTools version 2.37.3

[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
    • Android SDK at /Users/administrator/Library/Android/sdk
    • Platform android-34, build-tools 34.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 17.0.9+0-17.0.9b1087.7-11185874)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 16.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 16A242d
    • CocoaPods version 1.15.2

[✗] Chrome - develop for the web (Cannot find Chrome executable at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome)
    ! Cannot find Chrome. Try setting CHROME_EXECUTABLE to a Chrome executable.

[✓] Android Studio (version 2023.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 17.0.9+0-17.0.9b1087.7-11185874)

[✓] Connected device (2 available)
    • iPhone 16 Pro (mobile) • 98CC2EE2-66B2-49A0-852C-1390D3F4D39A • ios        • com.apple.CoreSimulator.SimRuntime.iOS-18-0 (simulator)
    • macOS (desktop)        • macos                                • darwin-x64 • macOS 15.0 24A335 darwin-x64

[✓] Network resources
    • All expected network resources are available.

! Doctor found issues in 1 category.

```

</details>