when client has been disconnected, but client.is_connected() is True

version： 1.6.1
python: 3.9.6

When I'm using paho-mqtt, sometimes in a weak network environment, there is an issue where the MQTT connection is actually disconnected, but according to client.is_connected(), the value is True, indicating that the client is still considered connected. I cannot rely on client.is_connected() to determine the connection status, which has led to significant bugs in my business logic. How can I solve this problem?