I would hard-reset the watch - sync, then press the Light button for some 30s till it completely shuts down (hold the button through the emergency alert, if it comes), wait little bit, and then restart. No worry, no data or settings will be lost with it. If it does not help, try the master reset to factory defaults. Also double check your bed and wakeup times, to see whether they are not inversed or misconfigured (happens easily when you use the default 12h format).
