Every time I hold the power button and the home button, it just takes a screenshot. Has Apple changed the way iPhones can be manually force shut down?
Force shutdown in iOS 10
I can't reproduce that. I have the opposite - when I press power + button, and then release, it takes a screenshot *AND* goes to the shutdown screen.
Pressing power + button and keeping them pressed does force shutdown as usual.
Just my experience, though.
FYI: I've added a bug on this for Beta 2: #27194497