I did not expectto find anyone with this exact same problem. Thanks for your post. I just upgraded my sdcard from an older pi to be used in this one. In my exact sme model, my raspi worked fine. Now it is the same as yours. Hereis what I suspect… I think the apt-gt upgrade affected the gpio library somehow. Looking at the script, shut down should only execute if the pin is high.

So question is, why does it think the pin is high? I will start work on this in the morning.