disconnect for return code 142

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- [ x] Bug exists Release Version 1.2.5 ( Master Branch)
- [ ] Bug exists in MQTTv3 Client on Snapshot Version 1.2.6-SNAPSHOT (Develop Branch)
- [ ] Bug exists in MQTTv5 Client on Snapshot Version 1.2.6-SNAPSHOT (Develop Branch)
I used the libarry org.eclipse.paho.mqttv5.client 1.2.5,connect to the mqtt broker broker.emqx.io
the connection always disconnected for as the log ：
disconnectResponse :MqttDisconnectResponse [returnCode=142, reasonString=null, userProperties=[], serverReference=null, exception=null]

Start by reproducing the disconnect with the Paho MQTT v5 client 1.2.5 against broker.emqx.io, using the reported disconnectResponse return code 142 as the initial symptom. Trace how the client handles that response and compare the broker interaction; done means the cause is identified and the issue has a verified fix or documented explanation.

Written by the indexing model from the issue text.