在React Native中，上下文更新不会重新渲染子组件

Question

addToCart的else部分正在实时实时更新。之后，useEffect以及subscriptionCart的数据都不会更新。其他所有设置都正确，没有问题。
另外，请在代码方面对我进行任何优化建议。此后，没有任何重新渲染，上下文状态只会被更新。

组件代码：

import React, {useContext, useEffect, useState} from 'react';
import {View, TouchableOpacity, Image} from 'react-native';

import Text from '../../../components/CustomText';
import colors from '../../../styles/colors';
import SubAddRemCont from './SubAddRemCont';

import {BASE_URL} from '../../../constants/ApiConstants';
import SubCartContext from '../../../context/SubCartContext';

const SubItemCard = ({product, navigation}) => {
  const [cartCount, setcartCount] = useState(0);

  const {subscriptionCart, addToCart, removeProdCount} = useContext(
    SubCartContext,
  );

  useEffect(() => {
    cartItemCount();
    console.log(
      'Step3:context updated in useEffect cartitemcount',
      subscriptionCart,
    );
  }, [addToCart, subscriptionCart]);

  console.log('Step4:context updated ', subscriptionCart);

  const cartItemCount = () => {
    subscriptionCart.forEach((obj) => {
      if (obj.itemId === product.itemId) {
        console.log('itemid', obj.itemId);
        setcartCount(obj.quantity);
      }
    });
  };

  if (!product) {
    return null;
  }
  return (
    <View
      style={{
        flexDirection: 'row',
        height: 150,
        borderRadius: 6,
        backgroundColor: colors.bg_white,
        elevation: 8,
        paddingTop: 23,
        paddingBottom: 18,
        paddingHorizontal: 16,
        marginBottom: 23,
      }}>
      <Image
        source={{uri: BASE_URL + product.image}}
        style={{width: 100, height: 100}}
      />
      <View style={{justifyContent: 'space-between', flex: 1}}>
        <TouchableOpacity>
          <Text style={{fontSize: 23, textAlign: 'left'}}>
            {product.itemName}
          </Text>
          <Text
            style={{
              fontSize: 14,
              textAlign: 'left',
            }}>
            Rs {product.itemPrice}/{product.baseUnit * 1000}gm
          </Text>
        </TouchableOpacity>
        <View style={{flexDirection: 'row', justifyContent: 'space-between'}}>
          <SubAddRemCont
            onPressAdd={async () => {
              console.log('Step1:addtoCart pressed in subItemCard component');
              addToCart(product);
            }}
            onPressRemove={async () => {
              removeProdCount(product.itemId);
            }}
            cartCount={cartCount}
          />
        </View>
      </View>
    </View>
  );
};

export default SubItemCard;

上下文代码：

const CartContext = React.createContext();

export const CartProvider = ({children}) => {
  const [cartData, setCartData] = useState([]);

  const initialiseCart = async () => {
    let retrieveCart = await AsyncStorage.getItem('CART_DATA');
    if (retrieveCart) {
      items = await JSON.parse(retrieveCart);
      setCartData(items);
    }
  };

  const updateCart = async (cartList) => {
    let data = JSON.stringify(cartList);
    await AsyncStorage.setItem('CART_DATA', data);
    setCartData(cartList);
    console.log('UPDATED_CART', cartList);
  };

  const addToCart = async (cartItem) => {
    const retrieveCart = await AsyncStorage.getItem('CART_DATA');
    let item = [];
    if (retrieveCart) {
      console.log('CART_NOT_EMPTY');
      item = await JSON.parse(retrieveCart);
      console.log('cartnotEmpty pushed');
      const filtered = item.filter((prod) => {
        console.log(prod.itemId, cartItem.itemId);
        return prod.itemId === cartItem.itemId;
      });

      if (filtered.length > 0) {
        console.log('SAME_ITEM_FOUND_INCRIMENT_QUANTITY');
        const pos = item
          .map((prod) => {
            return prod.itemId;
          })
          .indexOf(cartItem.itemId);
        item[pos].quantity += 1;
      } else {
        cartItem.quantity = 1;
        item.push(cartItem);
      }
    } else {
      cartItem.quantity = 1;
      item.push(cartItem);
    }
    SnackbarCustom('Product added to cart');

    updateCart(item);
  };

  const removeProdCount = async (itemId) => {
    const retrieveCart = await AsyncStorage.getItem('CART_DATA');
    let item = [];
    console.log('CART_NOT_EMPTY');
    item = await JSON.parse(retrieveCart);
    console.log('cartnotEmpty pushed');
    console.log('SAME_ITEM_FOUND_INCRIMENT_QUANTITY');
    const pos = item
      .map((prod) => {
        return prod.itemId;
      })
      .indexOf(itemId);
    item[pos].quantity -= 1;

    updateCart(item);
  };
  const addProdCount = async (itemId) => {
    const retrieveCart = await AsyncStorage.getItem('CART_DATA');
    let item = [];
    console.log('CART_NOT_EMPTY');
    item = await JSON.parse(retrieveCart);
    console.log('cartnotEmpty pushed');
    console.log('SAME_ITEM_FOUND_INCRIMENT_QUANTITY');
    const pos = item
      .map((prod) => {
        return prod.itemId;
      })
      .indexOf(itemId);
    item[pos].quantity += 1;

    updateCart(item);
  };

  const removeProd = async (itemId) => {
    const retrieveCart = await AsyncStorage.getItem('CART_DATA');
    const item = await JSON.parse(retrieveCart);
    const removeItems = item.filter((prod) => prod.itemId !== itemId);
    updateCart(removeItems);
  };

  const clearCart = async () => {
    updateCart([]);
    await AsyncStorage.removeItem('CART_DATA');
  };

  return (
    <CartContext.Provider
      value={{
        clearCart,
        cartData,
        addToCart,
        addProdCount,
        removeProdCount,
        initialiseCart,
        removeProd,
      }}>
      {children}
    </CartContext.Provider>
  );
};

export default CartContext;