Question from the React (legacy) test

Here is a component supposed to display the number of pixels scrolled vertically.

class Scroller extends React.Component{
  constructor(props){
    super(props);
    this.state={distance: window.scrollY};
    this.updateDistance= this.updateDistance.bind(this);
  }
  
  updateDistance(){
    this.setState({distance: window.scrollY});
  }
  
  componentDidMount(){
    window.addEventListener("scroll", this.updateDistance);
  }

  render(){
    return(
     <div style="height: 5000px">
       <p style="position: fixed; top: 5px; left: 5px">
          Scrolled{this.state.distance} pixels.
       </p>
     </div>
    );
  }
}

What is(are) the problem(s)?