If you've ever used the SNOOZ app, the unit could be in "Night mode" (which can be toggled on/off if you open the app and click on the light icon).
Alternatively, you can perform a hard reset on the device by following these steps:
1) Turn SNOOZ Pro on
2) Simultaneously press the volume up and down buttons for 5 seconds until SNOOZ Pro shuts off
3) Turn SNOOZ Pro back on and see if the problem persists
*Please note the hard reset will delete any timers you have set with the scheduler.