I have been struggling to send a custom error from within a flutter isolate.
I followed all the documentation, but I keep getting

Context

This is how I setup my isolates

Future<R> isolateRun<R>(FutureOr<R> Function() callback,
    {String? debugName}) async {
  final RootIsolateToken? token = RootIsolateToken.instance;
  assert(token != null);

     Isolate.current.addErrorListener(RawReceivePort((pair) async {
       final List<dynamic> errorAndStacktrace = pair;
       await FirebaseCrashlytics.instance.recordError(
         errorAndStacktrace.first,
         errorAndStacktrace.last,
       );
     }).sendPort);

    return await Isolate.run(() async {
      BackgroundIsolateBinaryMessenger.ensureInitialized(token!);
      DartPluginRegistrant.ensureInitialized();
      await initFirebase();  // This is where I call Firebase.initializeApp and define FlutterError.onError and PlatformDispatcher.instance.onError

      return callback();
    }, debugName: debugName);
  } else {
    return await computation();
  }
}

in the callback, I parse a fairly long JSON list, and my idea was to receive a Crashalytics report whenever one or more of the items in the list would fail parsing.

Something like

await isolateRun<List<Item>>(() {
      return jsonDecode(response)
          .map<Item?>((tagJson) {
            try {
              return Item.fromJson(tagJson);
            } catch (e) {
              getLogger().e("Could not parse this item ID $tagJson['id']}");
              FirebaseCrashlytics.instance.recordError(
                 e,
                 s,
                 reason: "Could not parse this item",
                 information: [tagJson],
              );
              return null;
            }
          })
          .whereType<Item>()
          .toList();
    });

However, I have spent a few hours trying all possible combinations, and I keep getting this error whenever I call FirebaseCrashlytics.instance.recordError

[FATAL:flutter/lib/ui/window/platform_message_response_dart_port.cc(53)] Check failed: did_send.

Any idea of the issue? Am I missing something?