Reorderable List glitches keyboard when not on home screen - flutter

Question

I am working on a project with textfields that are members of a reorderable list. My problem is when the list is accessed from a Navigator push to a new screen the text fields within the ReorderableListView on the new screen glitches causing the keyboard to pop up then quickly disappear. The code is identical for both lists, does anyone know what may be causing this bug? I created a sample main.dart to demonstrate the effect:
import 'package:flutter/material.dart';
void main() => runApp(App());
class App extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Reorderable List bug',
home: MainPage(),
);
}
}
class MainPage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Main Page'),
),
body: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Expanded(
child: ReorderableListView(
onReorder: (old_index, new_index) {},
children: <Widget>[
textCard(),
textCard2()
],
),
),
Text('Keyboard behaves as expected here but will glitch on following page'),
RaisedButton(
textColor: Colors.white,
color: Colors.blue,
child: Text('Go to SubPage'),
onPressed: () {
navigateToSubPage(context);
},
)
],
),
),
);
}
Future navigateToSubPage(context) async {
Navigator.push(context, MaterialPageRoute(builder: (context) => SubPage()));
}
}
class SubPage extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Scaffold(
body: ReorderableListView(
onReorder: (old_index, new_index) {},
children: <Widget>[
textCard(),
textCard2(),
RaisedButton(
key: ValueKey('3'),
textColor: Colors.white,
color: Colors.redAccent,
child: Text('Back to Main Page'),
onPressed: () {
Navigator.pop(context);
},
)
],
),
);
}
}
Widget textCard() {
return Card(
key: ValueKey('1'),
child: Padding(
padding: EdgeInsets.all(15.0),
child: Row(
children: <Widget>[
Padding(
padding: EdgeInsets.only(right: 15.0),
child: Text(
'1.',
)),
Expanded(
child: TextFormField(
decoration: InputDecoration(labelText: 'Enter text'),
)
)
],
)));
}
Widget textCard2() {
return Card(
key: ValueKey('2'),
child: TextFormField(
decoration: InputDecoration(
labelText: 'Enter text'
),
),
);
}