The CT clamp monitors the total household load (not just that of the charger) and will reduce power to the charger, should your total useage be within 10-15% of the incoming supply fuse rating.
The app should mirror that of the charger but, if the charger is showing 10A, I wouldn’t worry about it untill you have your car. However, if you have a 13A kettle, the charger is reading slightly low but, again I wouldn’t worry at this stage.