api实例的副本无法订阅合约

老师您好，我把api实例创建了一个副本，但是这个副本为什么不能订阅合约啊？显示获取行情超时

from threading import Thread
from tqsdk import TqApi,TqKq,TqAccount,TargetPosTask
import pandas as pd
import numpy as np
import time
from datetime import datetime
from datetime import date
#定义交易函数
def tqtest(api,code):  
    quote = api.get_quote(code) 
    print(code,quote.datetime,quote.last_price)                   
if __name__=='__main__':
    api_master = TqApi(TqKq(),auth="ywf8231757,ywf63359")
    t1 = Thread(target=tqtest, args=(api_master.copy(),'DCE.c2101'))
    t2 = Thread(target=tqtest, args=(api_master.copy(),'DCE.cs2101'))
    t1.start()
    t2.start()
    print('所有线程均已经开启')
    time.sleep(20)
    api_master.close()