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

[showfuture]

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?

[JiajiaHuang]

Version: 1.6.1 and 2.1.0
The same problem exists, causing BUG.

[MattBrittan]

Unfortunately it's not going to be possible to help without significantly more information (code, logs etc). In some cases the status of .is_connected() will not change immediatly as the connection is half open meaning the loss of connection will only be picked up by the keepalive process.