hi,team:

    my dag is 1 minute schedule,one parts dag state is success,but tasks state is not yet started in a dag:

![image](https://user-images.githubusercontent.com/41068725/116344664-357d8780-a819-11eb-8010-c746ffdfdbcc.png)


   how can to fix it?
airflow/settings.py
"""Configure ORM using SQLAlchemy"""
    from airflow.utils.log.secrets_masker import mask_secret
    log.debug("Setting up DB connection pool (PID %s)", os.getpid())
    global engine
    global Session
    engine_args = prepare_engine_args(disable_connection_pool)
    
    
    engine_args['encoding'] = conf.get('core', 'SQL_ENGINE_ENCODING', fallback='utf-8')
    if conf.has_option('core', 'sql_alchemy_connect_args'):
        connect_args = conf.getimport('core', 'sql_alchemy_connect_args')
    else:
        connect_args = {}
    engine = create_engine(SQL_ALCHEMY_CONN, connect_args=connect_args, **engine_args)
    mask_secret(engine.url.password)
    setup_event_handlers(engine)
    Session = scoped_session(
        sessionmaker(
            autocommit=False,
            autoflush=False,
            bind=engine,
            expire_on_commit=False,
        )
    )
def prepare_engine_args(disable_connection_pool=False):