The baby suddenly stops babbling, showing a dull expression, and is less lively. The baby is particularly thin, doesn’t like to eat, and sleeps late into the early hours of the morning, waking up at 2 AM for a nap. On the third day, the baby goes to bed at 10 AM, with only short periods of deep sleep during the day, about 2 hours. Why is the baby suddenly sleeping so late at night? Could there be something wrong with my baby?