I find an issue with my flutter project with go_router that the previous page is re-rendered when I navigate to another page with pushNamed.

I have the following setup

HomePage: route path: `/`
-- ScreenWithUniqueKey: route path/name: `screen_with_unique_key`
-- ScreenWithoutUniqueKey: route path/name: `screen_without_unique_key`
-- -- DetailPage: route path/name: `detail_page`

I added a print statement in the build function for each screen (not in HomePage) and here are the test results

• HomePage -> goNamed -> ScreenWithUniqueKey -> pushNamed -> DetailPage

build ScreenWithUniqueKey
build DetailPage
build ScreenWithUniqueKey

• HomePage -> goNamed -> ScreenWithUniqueKey -> pushReplacementNamed -> DetailPage

build ScreenWithoutUniqueKey
build DetailPage

• HomePage -> goNamed -> ScreenWithoutUniqueKey -> pushNamed -> DetailPage

build ScreenWithoutUniqueKey
build DetailPage
build ScreenWithoutUniqueKey

• HomePage -> goNamed -> ScreenWithoutUniqueKey -> pushReplacementNamed -> DetailPage

build ScreenWithoutUniqueKey
build DetailPage

Here is the example code and I run this code in https://dartpad.dev/ with Dart 3.4.1, Flutter 3.22.1 and go_router 14.1.4

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

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

final GoRouter _router = GoRouter(
  routes: <RouteBase>[
    GoRoute(
      path: '/',
      builder: (BuildContext context, GoRouterState state) {
        return const HomeScreen();
      },
      routes: <RouteBase>[
        GoRoute(
          path: 'screen_with_unique_key',
          name: 'screen_with_unique_key',
          builder: (_1, _2) => ScreenWithUniqueKey(key: UniqueKey()),
        ),
        GoRoute(
          path: 'screen_without_unique_key',
          name: 'screen_without_unique_key',
          builder: (_1, _2) => ScreenWithoutUniqueKey(),
        ),
        GoRoute(
          path: 'detail_page',
          name: 'detail_page',
          builder: (_1, _2) => DetailPage(),
        ),
      ],
    ),
  ],
);

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp.router(
      routerConfig: _router,
    );
  }
}

class HomeScreen extends StatelessWidget {
  /// Constructs a [HomeScreen]
  const HomeScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Home Screen')),
      body: Center(
        child: Column(
          children: [
            ElevatedButton(
              onPressed: () => context.go('/screen_with_unique_key'),
              child: const Text('Go to the Screen With Unique Key'),
            ),
            ElevatedButton(
              onPressed: () => context.go('/screen_without_unique_key'),
              child: const Text('Go to the Screen Without Unique Key'),
            ),
          ],
        ),
      ),
    );
  }
}

class ScreenWithUniqueKey extends StatelessWidget {
  const ScreenWithUniqueKey({super.key});

  @override
  Widget build(BuildContext context) {
    print('build ScreenWithUniqueKey');

    return Scaffold(
      appBar: AppBar(title: const Text('Screen With Unique Key')),
      body: Center(
        child: Column(
          children: [
            ElevatedButton(
              onPressed: () => context.pushNamed('detail_page'),
              child: const Text('Push Named to Detail Page'),
            ),
            ElevatedButton(
              onPressed: () => context.pushReplacementNamed('detail_page'),
              child: const Text('Push Reaplcement Named to Detail Page'),
            ),
          ],
        ),
      ),
    );
  }
}

class ScreenWithoutUniqueKey extends StatelessWidget {
  const ScreenWithoutUniqueKey({super.key});

  @override
  Widget build(BuildContext context) {
    print('build ScreenWithoutUniqueKey');

    return Scaffold(
      appBar: AppBar(title: const Text('Screen Without Unique Key')),
      body: Center(
        child: Column(
          children: [
            ElevatedButton(
              onPressed: () => context.pushNamed('detail_page'),
              child: const Text('Push Named to Detail Page'),
            ),
            ElevatedButton(
              onPressed: () => context.pushReplacementNamed('detail_page'),
              child: const Text('Push Reaplcement Named to Detail Page'),
            ),
          ],
        ),
      ),
    );
  }
}

class DetailPage extends StatelessWidget {
  const DetailPage({super.key});

  @override
  Widget build(BuildContext context) {
    print('build DetailPage');

    return Scaffold(
      appBar: AppBar(title: const Text('Detail Page')),
      body: Center(
        child: ElevatedButton(
          onPressed: () => context.pop(),
          child: const Text('Go back'),
        ),
      ),
    );
  }
}