Flutter WorkManager Pigeon -> Unable to establish connection on channel

Question

I have been using Pigeon to call Android native side for data. However when i try to do the same thing in a WorkManager task, it just throws PlatformException(channel-error, Unable to establish connection on channel., null, null).

I suspect the channel is not connectable if it is on a different thread managed by WorkManager, but I have no idea how to fix it.

Pigeon files

@HostApi()
abstract class BridgeApiNative {
  @TaskQueue(type: TaskQueueType.serialBackgroundThread)
  String helloNative(String world);
}

Flutter code

@pragma('vm:entry-point')
void callbackDispatcher() {
  Workmanager().executeTask((taskName, inputData) async {
    switch (taskName) {
      case "fetchBackground":
        BridgeApiFlutter.setup(BridgeApiFlutterImpl());
        BridgeApiNative().helloNative("hello!").then((value) => print("yeah $value"));
        // FIXME: PlatformException(channel-error, Unable to establish connection on channel., null, null)
        break;
    }
    return Future.value(true);
  });
}

Future<void> main() async {
  var instance = WidgetsFlutterBinding.ensureInitialized();
  await Workmanager().initialize(callbackDispatcher, isInDebugMode: true);
  await Workmanager().registerOneOffTask("1", "fetchBackground");
  runApp(const MyApp());
}

Android side

class MainActivity : FlutterActivity() {

    private lateinit var bridgeApiFlutter: BridgeApiFlutter

    override fun configureFlutterEngine(flutterEngine: FlutterEngine) {
        super.configureFlutterEngine(flutterEngine)
        bridgeApiFlutter = BridgeApiFlutter(flutterEngine.dartExecutor.binaryMessenger)
    }

    override fun onResume() {
        super.onResume()
        Log.e("MainActivity", "onResume")
        bridgeApiFlutter.helloFlutter("hello") {
            Log.e("MainActivity", "result: $it")
            // REMARK: This one works
        }
    }
}

Please help! Much appreciated!