Xbox is a weird setup, as they made a big fuss about IPv6 right back before Xbox One launched, but even Xbox Series X wont actually function on an IPv6 only stack - it still uses IPv4 to login to Xbox Live. Plus as I've mentioned many times, the fact it changes IP address every reboot as the UUID is generated on boot rather than once and retained until you factory reset, like every sane OS does including Windows (at least I'm fairly sure it does, not sure I've tried IPv6 on Windows).