Good afternoon and thank you for posting on the Final Fantasy XIV Technical Support Forums.

The primary cause of this issue seems to be related to Device Enumerator refreshing while playing the game. Normally, this will only refresh when a USB device is removed or plugged in. If this is happening without you intentionally doing one of those actions, then something else is causing this to refresh. Try removing any USB device that is not your mouse/keyboard and your controller.

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!