I’ve been working with Nuki 3.0 Pro (3.9.5 firmware version) and MQTT for 6 month without any issues.
However, in the last two weeks I’m experiencing repeated disconnections between the Nuki and the MQTT Message Broker (Mosquitto Broker).
After investigating it a bit, I saw the MQTT broker is sending the messages as expected but the Nuki does not pull the messages out of the queue and the messages keep pile up in the queue.
The only thing which helps is to get into the MQTT option in the Nuki lock and click the “save” button. I assume it makes the Nuki reconnect to the MQTT queue again.
I should mention nothing has changed in my current WIFI and Nuki has a full signal strength.
I Found that the keep_alive for NUKI MQTT is every 300 seconds and my broker was set to check keep_alive every 5 seconds. so i changed the keep_alive setting on my broker (EMQX) to check keep_alive every 300 seconds. and the issue resolved.