Red Alert Last Night

Our monitor issued a red alert last night and completely terrified myself and my husband. I sprung out of bed instantly to grab my daughter. She appeared completely fine - sleeping and calm (no gasping, no signs of distress)

When replaying the live feed, it does appear that she was motionless for several seconds, but we are thinking she was perhaps just in a very deep sleep since there was nothing out of the ordinary when we checked her after the alert.