If I click outside of Material UI Autocomplete input field then all text of input field got vanished

I'm using Material Ui Autocomplete component. So if you write something on that box and then click anywhere outside that input field your input field texts just got cleared out.How can I solve this problem?

import React from 'react';
import TextField from '@material-ui/core/TextField';
import Autocomplete, { createFilterOptions } from '@material-ui/lab/Autocomplete';

export default function Filter() {
  return (
    <Autocomplete
      id="filter-demo"
      options={top100Films}
      getOptionLabel={(option) => option.title}
      filterOptions={x => x}
      style={{ width: 300 }}
      renderInput={(params) => <TextField {...params} label="Custom filter" variant="outlined" />}
    />
  );
}