Unplug/Plug Power seems to re-send the last MQTT-Command

Hi there,
i’ve got a beginner-question regarding using OMG in combination with a mosquitto-mqtt server

I created a OMG-Board running sucessfully IR commands from MQTT, sent via my openHAB

But sometimes in the middle of the night, the TV gets turned on without anyone sending this command via MQTT

I now tested a bit and even if i only unplug, re-plug the device from/to microUSB power, the devices seems (maybe) to re-send the last sent command

Is this something normal, related to the MQTT-protocol and maybe has something to do with my MQTT-Broker settings regarding “retain” or something?

Sorry for the weird description but i fear that the error does not lie in OMG, but in some basic MQTT-settings


i found this

Disable retained message

Can you figure out how to disable the retain feature for a specific topic? It’s not as simple as sending a message with the retain flag set to 0, as that’s the default condition. Sending an empty message to the same topic with the retain flag set to 1 is the correct way to do it. Yes, this may appear counter intuitive, but it was done on purpose to avoid conflicts with any real time publishing on the same topic that did not have the retain flag set to 1.

The MQTT retained message feature is useful for preserving an object’s most recent state, which is especially useful when the state does not change frequently. The quality of the service settings has no impact on the messages that are retained.

Which seems to be what im looking for
Sending an empty message “clears” the retained message