react-navigation BottomTabNavigator VERY slow on some Android devices

Question

I've got a minimal test ReactNative test in Expo running. 2 screens, both just have Text within a View.

This is run on a MBP, and tested on my Android device (Note10+) via QR code.

It is not just slow, it's unresponsive most of the time, when it does navigate to a tab on click then it's either instant (rarely) or takes 5-10 seconds. But usually nothing happens.

There are no errors being shown, replacing the same code with a Stack or Drawer works fine.

2 basic screens:

function StackScreenA0({navigation}) {
  return (
     <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
        <Text>Test stack 0</Text>
        <Button title="goto 1" onPress={() => navigation.navigate('Screen A1')} />
     </View>
  );
}

function StackScreenA1({navigation}) {
  return (
     <View style={{ flex: 1, alignItems: 'center', justifyContent: 'center' }}>
        <Text>Test stack 0</Text>
        <Button title="goto 0" onPress={() => navigation.navigate('Screen A0')} />
     </View>
  );
}

App code (minus imports):

const Tab = createBottomTabNavigator();

function App() {
  return (
    <NavigationContainer>
      <Tab.Navigator initialRoutName='Screen A0'>
        <Tab.Screen name="Screen A0" component={StackScreenA0} />
        <Tab.Screen name="Screen A1" component={StackScreenA1} />
      </Tab.Navigator>
    </NavigationContainer>
  );
}
export default App;

I've never used Expo before but I can't imagine this is normal behaviour but cannot see a reason for it working so badly.

EDIT: I've found other devices to test and tabs are fine on iPad4, Galaxy9, but seriously bad on Note10+.

Rich