Scrollbar-bug

main.dart

import 'package:flutter/material.dart';

final Color darkBlue = Color.fromARGB(255, 18, 32, 47);

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark().copyWith(scaffoldBackgroundColor: darkBlue),
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: Center(
          child: MyWidget(),
        ),
      ),
    );
  }
}

class MyWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        SizedBox(
          height: 500,
          width: 500,
          child: Scrollbar(
            isAlwaysShown: true,
            child: ListView(
              children: [
                Container(height: 100, width: 20, color: Colors.red),
                Container(height: 100, width: 20, color: Colors.green),
                Container(height: 100, width: 20, color: Colors.red),
                Container(height: 100, width: 20, color: Colors.green),
                Container(height: 100, width: 20, color: Colors.red),
                Container(height: 100, width: 20, color: Colors.green),
              ],
            ),
          ),
        ),
        SizedBox(width: 30),
        SizedBox(
          height: 500,
          width: 500,
          child: Scrollbar(
            isAlwaysShown: true,
            child: ListView(
              scrollDirection: Axis.horizontal,
              children: [
                Container(height: 100, width: 100, color: Colors.red),
                Container(height: 100, width: 100, color: Colors.green),
                Container(height: 100, width: 100, color: Colors.red),
                Container(height: 100, width: 100, color: Colors.green),
                Container(height: 100, width: 100, color: Colors.red),
                Container(height: 100, width: 100, color: Colors.green),
              ],
            ),
          ),
        ),
      ],
    );
  }
}