Bug listening to AsyncNotifierProvider

main.dart

import 'dart:async';

import 'dart:math';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

final rnd = Random();

void main() => runApp(ProviderScope(child: MyApp()));

final counterProvider = AsyncNotifierProvider<Counter, List<int>>(() => Counter());

class Counter extends AsyncNotifier<List<int>> {
  final List<int> values = [];
  
  Counter();

  add(int value) async {
    state = await AsyncValue.guard(() async {
      values.add(value);
      return _readDatabase();
    });
  }

  @override
  FutureOr<List<int>> build() => _readDatabase();
  
  Future<List<int>> _readDatabase() async => values;
}

final counterManagerProvider = Provider((ref) {
  print("counterManagerProvider started listening");
  ref.listen(counterProvider, (prev, next) async {
    print("prev: $prev");
    print("next: $next");
  });
});

class MyApp extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    ref.watch(counterManagerProvider);
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Counter with Riverpod in Dartpad'),
        ),
        body: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              const Text(
                'You have pushed the button this many times:',
              ),
              LayoutBuilder(builder: (context, box) {
                final asyncValue = ref.watch(counterProvider);
                return asyncValue.when(
                    data: (data) => Text(data.toString(), style: Theme.of(context).textTheme.headline4,),
                    loading: () => Text("Loading"),
                    error: (e,s) => Text("Error $e $s")
                );
              })
            ],
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () async => await ref.read(counterProvider.notifier).add(rnd.nextInt(100)),
          child: const Icon(Icons.add),
        ),
      ),
    );
  }
}