I'm not sure how one of our devices because shared, but after I wiped it and started configuring it for a new user it started doing something I haven't come across yet. After connecting to WiFi and associating it with a user it would reboot and come up to an Apple ID login screen. There's no option to ignore. It also lost it connection to WiFi so I connected it to a Mac with internet sharing. I put in an Apple ID, and it tells me that only managed Apple ID's can be used. We have no managed Apple ID's.