DropdownButton is not dropping down in my custom header in Flutter - flutter

Question

I have a DropdownButton in my custom header widget that doesn't work. If I put the button in the content of the program it works fine, but not in the header. I get no errors.
This is the widget:
import 'package:flutter/material.dart';
class TestBar extends StatelessWidget {
const TestBar({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return Container(
alignment: Alignment.center,
height: 80.0,
color: Colors.white,
child: Row(
mainAxisAlignment: MainAxisAlignment.end,
mainAxisSize: MainAxisSize.min,
children: const [
Text('Text', style: TextStyle(fontSize: 18.0),),
SizedBox(width: 20.0,),
DropTest(
items: [
'Collections',
'Item 1',
'Item 2',
'Item 3',
],
),
SizedBox(width: 20.0,),
Text('Text', style: TextStyle(fontSize: 18.0),),
SizedBox(width: 20.0,),
],
),
);
}
}
class DropTest extends StatelessWidget {
final List<String> items;
const DropTest({Key? key, required this.items}) : super(key: key);
#override
Widget build(BuildContext context) {
return DropdownButton(
value: items[0],
elevation: 0,
style: const TextStyle(fontSize: 18.0),
icon: const Icon(Icons.keyboard_arrow_down_outlined, size: 20,),
underline: Container(height: 0,),
items: items.map<DropdownMenuItem<String>>((String value) {
return DropdownMenuItem<String>(
value: value,
child: Text(
value,
style: const TextStyle(fontSize: 18.0),
),
);
}).toList(),
onChanged: (String? newValue) {
switch (newValue) {
case 'Cucine':
return _goToPath(cucineRoute);
case 'Bagni':
return _goToPath(bagniRoute);
case 'Living':
return _goToPath(livingRoute);
default:
return;
}
},
);
}
}
void _goToPath(String navigationPath) {
//navigation to a certain page;
}
And this is where I use the header widget:
import 'package:flutter/material.dart';
import 'package:responsive_builder/responsive_builder.dart';
import 'package:sito_woodandstone/settings/constants.dart';
import 'package:sito_woodandstone/widgets/navigation_bar/test_bar.dart';
class LayoutTemplate extends StatelessWidget {
final Widget child;
const LayoutTemplate({Key? key, required this.child}) : super(key: key);
#override
Widget build(BuildContext context) {
return ResponsiveBuilder(
builder: (context, sizingInformation) => Scaffold(
backgroundColor: colorBackground,
body: Column(
children: [
const TestBar(),
//NavBar(),
Expanded(
child: child,
),
],
),
),
);
}
}
This is where the LayoutTemplate is used in the main function
import 'package:flutter/material.dart';
import 'package:sito_woodandstone/locator.dart';
import 'package:sito_woodandstone/routing/rout_names.dart';
import 'package:sito_woodandstone/routing/router.dart';
import 'package:sito_woodandstone/services/navigation_serivice.dart';
import 'package:sito_woodandstone/views/layout_template/layout_template.dart';
void main() {
setupLocator();
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Wood & Stone',
theme: ThemeData(
textTheme:
Theme.of(context).textTheme.apply(fontFamily: 'HeadingPro')),
builder: (context, child) => LayoutTemplate(child: child!),
navigatorKey: locator<NavigationService>().navigatorKey,
onGenerateRoute: generateRoute,
initialRoute: cucineRoute,
);
}
}
The Dropdown button below in the content is working but the one above is not image
I tried to remove the responsive builder but that is not the problem. I think there is something off in the main function, but I can't figure out what it is... Any ideas? Please help