I have a Fona mini that's working great when connected to my Raspberry Pi 3B. I am trying to now connect it to my pi zero W through the serial pins and not having much success. I'm following the
guide here; it seems to connect OK but when I run Screen it either displays rapidly rotating text, crashes straight out with "[screen is terminating]" or just locks up the pi completely and I have to reboot. What can I do to fix this?