Cambie los botones del screen y le puse un ScrollView component para que funcione en el celular

screens/main/Search.js

 import React, { useState } from 'react'
-import { Text, View,  StyleSheet, FlatList, TouchableOpacity } from 'react-native'
+import { Text, View,  StyleSheet, FlatList, TouchableOpacity, Button, ScrollView } from 'react-native'
 import SelectBox from 'react-native-multi-selectbox'
 import { xorBy } from 'lodash'
 import firebase from 'firebase'
 
 
   return (
+    <ScrollView>
     <View style={{ margin: 30 }}>
       <View style={{ width: '100%', alignItems: 'center' }}>
         <Text style={{ fontSize: 30, paddingBottom: 20 }}>Busqueda</Text>
       />
 
       {/* button that will fetch the users */}
-      <button onClick={() => fetchUsers(selectedTags, selectedDays)}>Buscar</button>
+      <Button title='Buscar' onPress={() => fetchUsers(selectedTags, selectedDays)}/>
 
 
       <FlatList
             <View style={{ flexDirection: "row", paddingBottom: 20, paddingTop: 20,  justifyContent: "space-between" }}>
               <Text>{item.data.name}</Text>
               <Text>{item.data.Precio}</Text>
-              <button  styles = {styles.button}     onClick={() => { dothing(item.id) }}>Button</button>
+              <Button title='Buscar' onPress={() => { dothing(item.id) }}/>
             </View>
             <View style={{ borderBottomColor: 'black', borderBottomWidth: 1 }} />
           </View>
         />
 
     </View>
+    </ScrollView>
   );
 
   function onMultiChange() {