lte.disconnect() failures...

[securigy]

I am constantly getting exception when calling lte.disconnect(), no matter what I do... My connection code is working fine.
After connecting I am pushing data with MQTT over CAT-M1. For some reason when I start the chunks of data (json strings) of about 400 bytes go through but then mqttClient.publish() fails with code 118, which is normally failure to connect...
Another strange thing is that after the code worked yesterday ok and mqttCleint.connect() was returning 0, today it returns 1. BTW, I am trying to connect to ThingsBoard... not sure if the setup there is related...

Anyway, I do not know if failure in MQTT (sockets) really affects LTE connection and cause lte.disconnect throw exception...
What say you?

if lte.isconnected():
        lte.disconnect()