[Solved] Kuled Smart Switch MQTT Disconnect Issue: OpenBeken v1.17.14, Reason 256, IP 192.168.0.50:1883

I have been using a Kuled smart switch flashed with OpenBeken for several months now and it has worked perfectly. Suddenly I can't control with MQTT. I have flashed to the current version 1.17.14 but still no luck. Here is a copy from the log file;

Info:MQTT:mqtt_userName homeassistant
mqtt_pass qqqqqqqqqq
mqtt_clientID den_light
mqtt_host 192.168.0.50:1883
Info:MQTT:mqtt_connection_cb: Successfully connected
Info:MQTT:mqtt_subscribed to den_light/+/set
Info:MQTT:mqtt_subscribed to cmnd/den_light/+
Info:MQTT:mqtt_subscribed to den_light/+/get
Info:MQTT:mqtt_subscribed to tele/den_light/+
Info:MQTT:mqtt_subscribed to stat/den_light/+
Info:MQTT:MQTT client in mqtt_incoming_publish_cb topic den_light/1/get
Info:MQTT:MQTT client in mqtt_incoming_publish_cb topic den_light/2/get
Info:MQTT:MQTT client in mqtt_incoming_publish_cb topic tele/den_light/STATE
Info:MQTT:mqtt_connection_cb: Disconnected, reason: 256(Disconnected)

Any clue what reason 256 tells me?

This is on the main web page:

MQTT State: disconnected RES: 0(ERR_OK)
MQTT ErrMsg:
MQTT Stats:CONN: 53 PUB: 0 RECV: 159 ERR: 0

Any help appreciated.

Bob

Hello, has anything changed on your network? Do you have any other OpenBeken devices running?

I have 10 other switches with OpenBeken installed and they are all working fine and connecting to my MQTT server without any problems. I'm not aware of any changes in my network. I actually have several APs and tried connecting to a different AP and the MQTT still wouldn't connect.

Any ideas?

Bob

Added after 25 [minutes]:

Shortly after the last email I set flags 2 and 10 and then did a restart and this time it worked. I had tried to restart several times before and it didn't work. I'm not sure what was different this time or how long it will last but it's working now.
Thanks,
Bob

I have currently no idea what might be wrong.

I can see some other LWIP users had similar issue on STM:
https://community.st.com/s/question/0D53W00000as7G6SAI/stm32f767-mqtt-using-lwip

They suggest increasing LWIP memory size, but I think we already allocated enough on LWIP:

And it happened to you randomly... hm please report here if anything else strange happens with your MQTT

Restarting the module appeared to eventually solve the problem.
Thanks,
Bob