React-Native-Component not rendering when state is changed

I am making the show more and show less functionality inside a flat list but the state pressed is not working as expected .When I am setting the state value component is not being rendered when the state changes its value.

My constructor is set like below

this.state = {
            accList: [],
            expanded: false,
            expandedText: "Show More"
        }

In componentdidmount() I am updating the value of accList value like below

componentDidMount = () => {
      this.setState({
accList:[{
    "customer_name": "Shubhangi J Thakur",
    "message":"Hello"
},
{
    "customer_name": "Arthur S Campbell",
    "message":"Hello_World"
},
{

    "customer_name": "Susan R Brill",
    "message":"hellow"
}]
});

    }

I have defined the flatlist in render() like below

<FlatList
     onScroll={this.handleScroll}
     data={this.state.accList}
       renderItem={this.renderItem}
        keyExtractor={this._keyExtractor}
    />

    renderItem = ({ item, index }) => (
        <Card style={style.cardLayout} key={index}>
            <CardItem header>

              <Text>{item.customer_name}</Text>

            </CardItem>
            {this.seemorefunctionality(item)}

        </Card>
    );


    seemorefunctionality = (item) => {

              return <View>

            {this.state.expanded ? this.expandedView(item) :null}
//To view Show More and Show Less Text
                <TouchableOpacity onPress={this.expandedText}>
                 <Text> {this.state.expandedText}</Text>
                </TouchableOpacity>
              </View>

            }
          } 



expandedText = () => {
        console.log('Setting the expanded text value', this.state.expanded)
         if (this.state.expanded) {
           this.setState({
             expandedText: "Show More"
           });
         }
         else {
           this.setState({
             expandedText: "Show Less"
           });
         }
         value=!this.state.expanded
         this.setState({
           expanded: value

         });
       }


expandedView = (item) => {
        return   <View>
             {item.map((obj, index) => {
               return (
                 <View key={index} >
                 <Text>{obj.message}</Text>
                 </View>
               )
             })}
           </View>

When I am clicking on the this.state.expandedText value is getting changed when we see in the console but its not reflecting in the View also expandedView is not being rendered when this.state.expanded is set to true.
In View the value of this.state.expandedText is always showing Show More while I can see In console that the value is getting changed to Show more and Show Less on click