SARA R410M fails to connect to MQTT server after a few successful attempts

With the module connected, registered and attached to the NB-IoT network, without PSM active, an error occurs after a few (usually 6-7) login - send data - logout actions. The module has the latest firmware.

A detailed list of AT commands and results follows:

AT+CGATT?

<< +CGATT: 1

<< OK

AT+CSQ

<< +CSQ: 16,99

<< OK

AT+CGDCONT?

<< +CGDCONT: 1,“IP”,“APN_address_Edited”,“10.21.1.145”,0,0,0,0

<< OK

AT+UMQTTNV=0

<<

<< +UMQTTNV: 0,1

<< OK

AT+UMQTT=0,“Topic”

<<

<< +UMQTT: 0,1

<< OK

AT+UMQTT=3,“5.196.95.208”,1883

<<

<< +UMQTT: 3,1

<< OK

AT+UMQTT=12,1

<<

<< +UMQTT: 12,1

<< OK

AT+UMQTTC=1

<<

<< +UMQTTC: 1,0

<< OK

MQTT failed

AT+UMQTTC=1

<<

<< +UMQTTC: 1,0

<< OK

MQTT failed

AT+UMQTTER

<<

**<< MQTTER: 350,-20025

<< OK

AT+UMQTTC=0

<<

<< +UMQTTC: 0,0

<< OK

Has anyone encountered the same issue?

Hi @darius.popa,

We also have encountered issues with the build-in MQTT of u-blox.

Does any of these suggestions help:
https://support.sodaq.com/Boards/Sara_AFF/faq/#mqtt

Best regards,
Jan

Hello @Jan,

We shall try the new library and let you know.
Thank you for the answer.

Best Regards,
Darius