Warning message in the expo app

When executing the code below in the expo app, it works however with the following warning message: Warning: Failed child context type: Invalid child context virtualizedCell.cellKey of type number supplied to CellRenderer , expected string .

import React, { Component } from 'react'
import {
  Text,
  View,
  StyleSheet
} from 'react-native'
import List from './src/components/List'

export default class App extends Component {
  render () {
    return (
      <View style={[{flex: 1}, styles.container]}>
        <List /> 
      </View>

    )
  }
}

const styles = StyleSheet.create({
  container: {
    backgroundColor: 'black'
  }
})

.........

class List extends Component {

    _renderItem(item) {
        return (
            <Image style={{width: 120, height: 180}} source={{uri: item.image}} />
        )
    }
_renderItem(item) {
        return (
            <Image style={{width: 120, height: 180}} source={{uri: item.image}} />
        )
    }

    render () {
        return (
            <View style={{flex: 1}}>
                <View>
                    <Text style={styles.text}>My List</Text>
                    <FlatList 
                        horizontal
                        ItemSeparatorComponent ={() => <View style={{width: 5}}/>}
                        renderItem={({item}) => this._renderItem(item)}
                        data={shows_first}
                    />
                </View>
                <View>
                    <Text style={styles.text}>Top Picks For You</Text>
                    <FlatList 
                        horizontal
                        ItemSeparatorComponent ={() => <View style={{width: 5}}/>}
                        renderItem={({item}) => this._renderItem(item)}
                        data={shows_second}
                    />
                </View>
            </View>
        )
    }
}

const styles = StyleSheet.create({
    text: {
        color: 'white'
    }
})

export default List