Latitude 12-5285 Magnetic Lid shuts off machine... Won't turn back on

I've got the problem that the magnet on my keyboard cover shuts off my tablet if it's on or asleep. When I try to turn the device back on, it won't come up. I have to long-press the power button, shut the device down, and reboot. I've tried telling it not to sleep when the lid is closed, but that does nothing useful in this case. Does anyone have any suggestions?