After the Snooze period is over, the device should automatically wake-up and return to Armed mode but if at that time the device does not have cellular connection, an error may occur and the status of the device will remain in Snooze mode in the App.
Try using App - Device Settings (Phone/Tracker in Bluetooth range) - Test Device Connection to see if it can push the device to wakeup manually. Contact the support team via support@monimoto.com or in-App message in case this still does not help.