Why does my selenium return the result which is not my respect randomly?

python selenium the website is http://xkz.cbirc.gov.cn/jr/，reflush it and you will find the confirm messageBox

driver.get("http://xkz.cbirc.gov.cn/jr/")
wait = WebDriverWait(driver, 10)

table_yanZhengMa = wait.until(EC.presence_of_element_located((By.XPATH, "/html/body/div[5]/table")))
print(table_yanZhengMa)

visibilityMy = driver.find_element_by_id("show_msg").get_attribute('style')  
print(visibilityMy)
if(visibilityMy.find("visibility: visible")>=0):
    print("you must input confirm letters")

randomly, the html file contains

but i only get "z-index: 20001; width: 450px;" this appears randomly,but i want to fix it,how to fix it?

error picture1 error picture2