@Jvaha 

Hi, 
It's suggested to check if the problem is related to your Alarm settings on the Tapo app. You can go to the Tapo app and go to the Camera Settings page>Detection&Alerts>Camera Alarm to check the Alarm settings, if you have set an alarm schedule, the alarm may turn off according to the schedule you set without opening the Tapo app to turn it off manually.
By the way, the camera alarms only when it detects activity.
Best Regards