How to know if element appear and then disappear in selenium python ' is_displayed() issues '

Question

In the website i'm trying to automate, when the internet connection get lost a notification you can access to it by a class name appears at the top of the page and tells you that there is no internet and i want to code something that let you pause the process until the internet get back and i'm tying to reack that by .is_displayed() which return a True value after checking that the notification appears and it's working fine but when i tried to check the disappear of the element it show me an error

except:
#time.sleep(3)
if driver.find_element(By.CLASS_NAME, "HGcYc4pY").size['width'] != 0 :
    print ('internet lost')
    while True:
        c= driver.find_element(By.CLASS_NAME, "HGcYc4pY").is_displayed()
        if driver.find_element(By.CLASS_NAME, "KhLQZTRq pxYtrw1j D56bmevE").is_displayed() == True:
            print("still lost")
        if driver.find_element(By.CLASS_NAME, "KhLQZTRq pxYtrw1j D56bmevE").is_displayed() == False:
            print("interent is back")
            break   
print("did it ")          

I tried this and it's just the same it doesn't work when the notification disappear aggain

except:
    #time.sleep(3)
    if driver.find_element(By.CLASS_NAME, "HGcYc4pY").size['width'] != 0 :
        print ('internet lost')
        while True:
            if driver.find_element(By.CLASS_NAME, "HGcYc4pY").size['width'] != 0:
                print("still lost")
            if driver.find_element(By.CLASS_NAME, "HGcYc4pY").size['width'] == 0:
                print("interent is back")
                break   
    print("did it ")