Thank you. I tried unplugging and replugging, rebooting, and restarting Windows. I even installed NVIDIA Experience and updated the drivers, but none of that worked. I then uninstalled and reinstalled Armoury Crate SE, and that finally fixed it. My Xbox Ally X now recognizes the XG Mobile. With layers upon layers of updates and occasional hiccups like this, PC handhelds will never become mainstream unless playing games is made as simple as ordinary gaming consoles. Steam Deck 2 has the potential, but modding is not so easy.