Function only delete last item from an array

Question

In react native, I'm using those functions to save and delete items from an array but it only delete last item, what I'm supposed to change ?

SaveValue = () => {
  const newFavs = [...this.state.favs, this.state.UserInput];
  this.setState({ favs: newFavs, UserInput: '' }, () => {
      AsyncStorage.setItem("Favorites", JSON.stringify(this.state.favs));
      Keyboard.dismiss()
  });
};

FetchValue = () => {
  AsyncStorage.getItem("Favorites").then((value) => {
    this.setState({
      favs: JSON.parse(value)
    });
  }).done();
};


RemoveValue(item){
    const index = this.state.favs.indexOf(item);
    const newArray = [...this.state.favs];
    newArray.splice(index,1);
    this.setState({ favs: newArray });
    AsyncStorage.setItem("Favorites", JSON.stringify(newArray));
}