Windows 11 keeps resetting my audio output device back to default

The key distinction is whether Windows forgets your preference or the USB headset is unavailable when audio devices are initialized. Before changing more sound effects, restart with the headset connected directly to the same USB port, then immediately check Settings, System, Sound. If the headset is missing, investigate detection or its driver first; Windows cannot select an unavailable output. If it is present, open the Playback tab in the Sound Control Panel and check the default designation before launching your usual applications. Compare Windows' test sound with the application that plays through the speakers, because an application-specific output setting can differ from the system default. Your changes to enhancements and exclusive mode do not establish which of these situations applies. Record the headset model, whether a dock is involved, and whether replugging alone restores the expected device. Avoid deleting other audio endpoints until the actual failure is identified.