MKR NB 1500 connection to IOT Hub

Hi everyone, I’m fairly new to Arduino and I have a problem with my MKR NB 1500. I use the sketch to connect to Azure IOT Hub with MQTT client. I manage to get a connection, but after some hours, the connection breaks off for no clear reason.
Does anyone recognize this behavior and have some suggestions that can point me in the right direction? I am using a 1nce SIM card and I have an antenne and a 3.7V 10000mAh battery attached.

It’s not uncommon. Many examples have reconnection logic in them for just this reason.