How to deal with Flutter Local Storage gives a File Exception "an async operation is currently pending"?

Question

I have the function below where i call another async function "getAnimeById( )".

Whenever I hot restart my app, i get the file exception and the set that is loaded has duplicates.

Future<void> fetchRecommendations() async {
    //grab data from local disk
    LocalStorage storage = LocalStorage("recommended_data");

    await storage.ready;

    //clear the set to avoid showing anime that arent in the list anymore
    _recommendedSet.clear();

    Map tempMap;

    //try to fetch data, if not available create it
    try {
      tempMap = await storage.getItem("recommendedMap");
    } catch (error) {
      tempMap = {};
    }

    for (var element in tempMap.keys) {
      if (!animeData.containsKey(element)) {
        await getAnimeById(element);
      }
      final tempAnime = animeData[element]!;

      checkIndex += 1;

      _recommendedSet.add(tempAnime);
    }

    notifyListeners();
  }

Future<void> getAnimeById(String id) async {

....

LocalStorage storage = LocalStorage("episode_data");

      await storage.ready;

      Map<String, dynamic> episodeMap = {};

      // if the episode data does not exist we continue with an empty map
      try {
        episodeMap = storage.getItem("episodeMap");
      } catch (error) {
        episodeMap = {};
      }

.....




try {
        await storage
            .setItem("episodeMap", episodeMap)    //This is the line that throws the error
            .then((value) => storage.dispose());
      } catch (error) {
        print(error);
      }



}

The above code works fine after the home screen is pushed again on the navigator stack. It only happens when the app is started fresh.

I also found that the error happens only for certain indexes in the loop in the first function.