Did you also update the modem firmware (not just the FiPy board firmware)?
You can follow the steps described here: https://docs.pycom.io/tutorials/lte/firmware/
We’ve made the modem firmware available in this GitHub repository, since Pycom has password protected the files on their server: https://github.com/TelenorStartIoT/sequans-modem-firmware
In your case you want the LTE-M (Cat M1) firmware.
You can also try the commands that are described at the top of this thread. You can access the REPL (the window where you can read the program output) by pressing
CTRL + C. This will stop the program and give you three arrows
>>> where you can type your Python code line-by-line. It should look like this if you’ve entered the REPL successfully:
Hope this helps!