AC2300 WiFi Router (R7000P)

Hello, I have a Netgear Nighthawk AX2.300 smart Wi-Fi router, Model R7000P. I am trying to change the device name on an Xbox One, of which we have three on the Wi-Fi. I see where I can edit the device name and model, but it won't let me. I keep getting an error message. One message says error (symbol), but I am not using a symbol, just letters. Do you have any idea how to get it to apply?

Thanks!