1import { Keyboard } from 'react-native';
2Keyboard.dismiss()

1<ScrollView contentContainerStyle={{flexGrow: 1}}
2  keyboardShouldPersistTaps='handled'
3>
4  <TextInput keyboardType='numeric'/>
5</ScrollView>

1It's because the ListHeaderComponent from the FlatList is being re-render each time you change the state. I'm not sure to see a quick solution to fix in this context of usage.
2
3Even though if you have the possibility to use HeaderComponent instead I would recommend you do that: https://snack.expo.io/@jeremdsgn/modalize-issue
4
5I'm closing this issue