Cellular boards to use to connect to Azure

Hey all. I am trying to connect to Azure IoT hub via MQTT, requiring the use of SSL certs. I began by trying the MKR1400 GSM. However, I found this solution to be unreliable. It was able to sometimes connect to Azure, but not always. I believe this is a known issue, linked to the hardware, so I moved on. Being able to consistently and reliably connect is a must for me.

What I am using now is a Sim800h and a MKRZERO. With this, I can connect to an "unsecure" MQTT broker reliably. However, when trying to connect to Azure, I find it harder. I've done the usual things to try debug this (including updating the firmware), but I still cannot connect to Azure. I've tried multiple libraries, even sending AT commands manually. There appears to be multiple other people noting the same behaviour on forums and Github issues. Potentially, I need a new board.

My question then contains two interlinked parts:

  • has anyone successfully connected to Azure IoT hub using an Arduino and a cellular board?
  • If I were to buy a new cellular board, are there things people here would recommend?

thanks