Room does not insert data to table

It is interesting point that it sometimes performs insert operation correctly. I do not know why and how this situation can be happens. So, I could not figure out where I made a mistake(s). Here is my project files.

1) SentFilesDao.java

@Dao
public interface SentFilesDao {
    @Query("SELECT id, name, type, status, dateTime FROM sent")
    LiveData<List<SentFilesEntity>> getAllSentFiles();

    @Insert(onConflict = OnConflictStrategy.IGNORE)
    void insert(SentFilesEntity file);

    @Query("DELETE FROM sent")
    void deleteAllRecords();
}

2) SentFilesRepository.java

public class SentFilesRepository {
    private SentFilesDao mSentFilesDao;
    private LiveData<List<SentFilesEntity>> mAllSentFiles;

    SentFilesRepository(Application application) {
        AppDatabase db = AppDatabase.getDatabase(application);
        mSentFilesDao = db.mSentFilesDao();
        mAllSentFiles = mSentFilesDao.getAllSentFiles();
    }

    LiveData<List<SentFilesEntity>> getAllSentFiles() { return mAllSentFiles; }

    public void insert(SentFilesEntity sentFilesEntity) {
        new SentFilesRepository.insertAsyncTask(mSentFilesDao).execute(sentFilesEntity);
    }

    private static class insertAsyncTask extends AsyncTask<SentFilesEntity, Void, Void> {
        private SentFilesDao mAsyncTaskDao;

        insertAsyncTask(SentFilesDao dao) {
            mAsyncTaskDao = dao;
        }

        @Override
        protected Void doInBackground(final SentFilesEntity... params) {
            mAsyncTaskDao.insert(params[0]);
            Log.e("doInBackground: ", "reached here!"); // no any log in Logcat about this. Weird...
            return null;
        }
    }
}

3) SentFilesEntity.java

@Entity(tableName = "sent")
public class SentFilesEntity {
    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = "id")
    public int s_f_id;

    @ColumnInfo(name = "name")
    public String s_f_name;

    @ColumnInfo(name = "type")
    public String s_f_type;

    @ColumnInfo(name = "status")
    public String s_f_operation_status;

    @ColumnInfo(name = "dateTime")
    public String s_f_time;
}

4) SentFilesViewModel.java

public class SentFilesViewModel extends AndroidViewModel {
    private SentFilesRepository mRepository;
    private LiveData<List<SentFilesEntity>> mAllSentFiles;

    public SentFilesViewModel(Application application) {
        super(application);
        mRepository = new SentFilesRepository(application);
        mAllSentFiles = mRepository.getAllSentFiles();
    }

    public LiveData<List<SentFilesEntity>> getAllSentFiles() { return mAllSentFiles; }

    public void insert(SentFilesEntity sentFile) { mRepository.insert(sentFile); }
}

What I am trying to do:

My program sends selected files from one device to another one through WiFi Direct. As file received or sent, I want to save some information about file (such as file name, file type (image, video, music, APK and etc.), send/receive date and time) and operation (succeeded or failed). I can handle all these things.

What is the problem?

Well, getting all the properties (those I mentioned above), is not end. Main problem is saving that data to database. To do that I created some required files (I shared their codes above). When file sent, I am trying to insert related information to database. But it does not insert it. That is the my problem.

Well, main codes are too long to post here. However I posted my latest codes to my GitHub project and the main logic starts from here and it connected to FileStatisticsActivity.

p.s: Maybe sharing the project link is not ethic, I am so sorry for that.

Thanks.