I've manually gone online to my windows account and changed my name there, but it doesn't appear on reboot of any of my devices. Occassionally, it will do it the first time after reboot if I try to change it to something else. When I try to go change my name again, it displays my old name as the account name, but when I click edit name, it's whatever I've most recently changed it to. It's not because I've changed it frequently either, because I've only been changing it so much because it didn't work the first time.