Duplicated user interface on restart

When I launch the application, then everything is fine. The user interface works as expected. But when I close the application and remove it from the phone memory, the service stops and it can no longer be started. When you restart the application, a new window with the interface opens, and the first one does not disappear. Only the second window works. A lot of interface windows can be created this way. What could be the problem? And how to close the window when the application is removed from memory?

void main() async {
      WidgetsFlutterBinding.ensureInitialized();
      MobileAds.instance.initialize();
    
      await setupServiceLocator();
    
      runApp(const MyApp());
    }
    
    
    import 'package:audio_service/audio_service.dart';
    import 'package:get_it/get_it.dart';
    import 'audio_player_handler.dart';
    import 'data.dart';
    import 'home.dart';
    
    
    GetIt getIt = GetIt.instance;
    
    Future<void> setupServiceLocator() async {
      // services
      if(!getIt.isRegistered<AudioHandler>()) {
        getIt.registerSingleton<AudioHandler>(await initAudioService());
      }
    }
    
    
    import 'package:audio_service/audio_service.dart';
    import 'package:just_audio/just_audio.dart';
    
    
    final audioPlayer = AudioPlayer();
    
    Future<AudioHandler> initAudioService() async {
      return await AudioService.init(
        builder: () => AudioPlayerHandler(),
        config: AudioServiceConfig(
          androidNotificationChannelId: 'top.musicplus.audio',
          androidNotificationChannelName: 'Audio Service Demo',
          androidNotificationOngoing: true,
          androidStopForegroundOnPause: true,
          androidNotificationIcon: 'drawable/fone_start'
        ),
      );
    }
    
    class AudioPlayerHandler extends BaseAudioHandler with SeekHandler {
    
      /// Initialise our audio handler.
      AudioPlayerHandler() {
        audioPlayer.playbackEventStream.map(_transformEvent).pipe(playbackState);
      }
    
      @override
      Future<void> updateMediaItem(MediaItem mediaItem) async {
        this.mediaItem.add(mediaItem);
      }
    
      @override
      Future<void> play() => audioPlayer.play();
    
      @override
      Future<void> pause() => audioPlayer.pause();
    
      @override
      Future<void> stop() => audioPlayer.stop();
    
      @override
      PlaybackState _transformEvent(PlaybackEvent event) {
        return PlaybackState(
          controls: [
            //MediaControl.rewind,
            audioPlayer.playing ? MediaControl.pause : MediaControl.play,
            //MediaControl.stop,
            //MediaControl.fastForward,
          ],
          systemActions: const {
            MediaAction.seek,
            MediaAction.seekForward,
            MediaAction.seekBackward,
          },
          // androidCompactActionIndices: const [0, 1, 3],
          androidCompactActionIndices: const [0],
          processingState: const {
            ProcessingState.idle: AudioProcessingState.idle,
            ProcessingState.loading: AudioProcessingState.loading,
            ProcessingState.buffering: AudioProcessingState.buffering,
            ProcessingState.ready: AudioProcessingState.ready,
            ProcessingState.completed: AudioProcessingState.completed,
          }
          [audioPlayer.processingState]!,
          playing: audioPlayer.playing,
          updatePosition: audioPlayer.position,
          bufferedPosition: audioPlayer.bufferedPosition,
          speed: audioPlayer.speed,
          queueIndex: event.currentIndex,
        );
      }
    }