行情接受中更新主力合约返回空列表

query_cont_quotes这个方法必须行情开盘后才能获取，但是我下面代码一开始函数里调用query_cont_quotes没有问题，但是我放到一个定时任务里过几秒才去更新调用同样方法就返回空列表为何

async def _schedule_main_code_update(self):
    """定时更新main_code（只执行一次）"""
    while True:
        now = datetime.datetime.now()
        if 15<=now.hour <= 16 and now.minute == 2 and 1<=now.second <= 10:
            self.get_main_code()
            break
        elif 20<=now.hour <= 21 and now.minute == 0 and 1<=now.second <= 10:
            self.get_main_code()
            break
        elif now.hour > 21:
            break
        else:
            await asyncio.sleep(1)

def update_live_data(self):
"""对外接口:实时更新所有数据"""
self.get_main_code()
print(f"[{datetime.datetime.now()}] data server start",flush=True)
self.api.create_task(self._schedule_main_code_update())
for i in self.input_task:
self.api.create_task(self.insert_latest(i, 60))
self.api.create_task(self.insert_latest(i, 300))
self.api.create_task(self.insert_latest(i, 86400))
self.api.create_task(self.get_quote(i))