Textinput disappear in ios if screen load again in react native

Question

if i load screen first time then textinput is visible , but when navigate to screen again then textinput is disappear, but the same thing is working fine in android

<TextInput
   style={styles.input}
   editable={this.state.isLoading == true ? false : true}
   placeholderTextColor={MyColors.placeHolderColor}
   value={this.state.mobileNumber}
   onChangeText={val => textMobileNumberCheck(val)}
   placeholder="Enter mobile number"
   keyboardType="numeric"
   maxLength={10}
/>

const styles = StyleSheet.create({
 input: {
    height: 45,
    backgroundColor: '#fff',
    paddingVertical: 5,
    paddingHorizontal: 12,
    borderColor: '#ccc',
    marginHorizontal: 20,
    marginBottom: 5,
    marginTop: 15,
    color: '#000',
    marginTop: 15,
    borderWidth: 1,
    borderRadius: 5,
    fontSize: 16,
    marginBottom: 20,
  },
 
});