Minimum Reproducible of Unfocusable Keyboard when there is GoRouter and ScreenUtil in a Flutter Project.

main.dart

import 'dart:convert';
import 'dart:math';

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

void main() => runApp(const MyApp());

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

  @override
  Widget build(BuildContext context) {
    return ScreenUtilInit(
      designSize: const Size(392, 872),
      ensureScreenSize: true,
      builder: (context, _) {
        return MaterialApp.router(
          routerConfig: GoRouter(
            routes: [
              GoRoute(path: '/', builder: (_, __) => const FormScreen()),
              GoRoute(path: '/:path(.*)', redirect: (_, __) => '/'),
            ],
          ),
          theme: ThemeData(
            colorSchemeSeed: Colors.blue,
            brightness: MediaQuery.of(context).platformBrightness,
            useMaterial3: true,
          ),
        );
      },
    );
  }
}

class FormScreen extends StatefulWidget {
  const FormScreen({super.key});

  @override
  State<FormScreen> createState() => _FormScreenState();
}

class _FormScreenState extends State<FormScreen> {
  final _formKey = GlobalKey<FormState>();
  final _titleCtrl = TextEditingController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Form/GoRouter/ScreenUtil')),
      body: Form(
        key: _formKey,
        autovalidateMode: AutovalidateMode.onUserInteraction,
        child: ListView(
          padding: EdgeInsets.all(min(32.r, 32)),
          children: [
            TextFormField(
              controller: _titleCtrl,
              decoration: const InputDecoration(label: Text('Title')),
              validator: (v) => v == null || v.isEmpty ? 'Required' : null,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        heroTag: null,
        tooltip: 'Save',
        child: const Icon(Icons.cloud_done),
        onPressed: () {
          if (_formKey.currentState!.validate()) {
            debugPrint(jsonEncode({'title': _titleCtrl.text}));
          }
        },
      ),
    );
  }
}