In the Mendix MQTT Connector, there is no option to manually set the MQTT client ID. Even worse, it is automatically generated each time the app starts. As a result, the persistence feature provided by the MQTT protocol cannot be utilized, leading to message loss upon a restart or failure. With a static (or manually set) client ID, missed messages can be received after a restart, so no messages are lost. See MQTT Version 5.0 specification, e.g. MQTT Version 5.0 for reconnecting using the same client ID or MQTT Version 5.0 for message resending.