Subject: [Bug] ESP32: MQTT event

Hello,

I am experiencing an issue with the MQTT library on an ESP32 board. The connection to the broker (Adafruit IO) and the topic subscription (MQTT sub) both complete successfully. This is confirmed by debug messages and the ability to reliably publish data (MQTT pub). However, the when MQTT event block never triggers when a message is published to the subscribed topic. I have tested this with a minimal script that only displays the payload, but it still does not work. This suggests a bug in how incoming messages are handled, as they are not triggering the event block.