My Managers Are Making Us Work Off The Clock

I work as a late night delivery driver for a popular pizza place in town and I often am a closing driver. Closing staff usually consists of 1 manager, and 2 delivery drivers, who each have their own list of closing duties to complete. (Please keep in mind that we are severely understaffed and work at the most popular, and accessible, location.) Lately they’ve been complaining that labor is too high, and that people were gonna start getting written up if it didn’t change. So their solution was to give us exactly 1 hour to complete closing chores. If the opening manager sees that the closing crew didn’t finish their tasks on the list, the whole closing crew gets written up. (3 write ups and you can be fired.) Should I keep working past when they stop paying me to avoid being fired, or do I leave as soon as I’m no longer getting paid for my overtime?