We have had drought and then nearly 200ml of rain we were away when we got the rain when we got home yesterday the trees leafs have rolled under,the leafs are really green and healthy looking and doesn’t seem to have any pest it also has a lot off fruit on it it is only 2 years old and struggled from the begging it really does look the best it has been thank you for tour time
You are likely seeing the results of the uneven watering of the Citrus Tree.
Tree should be regularly watered. Make sure the soil is well draining to ensure the roots do not sit in wet soil.
This article has more information.