Power shutoff isn't using the automation signal I give it. It has a player-controlled switch and uses that instead.
EDIT: Actually wait. Looks like the automation signal is actually working, but it can be overridden by the manual switch. I don't remember that being there before, was it intended to be added?
1. Build a Power Shutoff
2. Connect an automation wire to it
EXPECT: Power Shutoff turns on and off according to the automation signal
ACTUAL: Power Shutoff turns on and off based on player switch