CodeyOverflow Forum - white screen

I have been struggling with the exercises in React 101. Currently getting a white screen, no errors, for this one - https://www.codecademy.com/courses/react-101/projects/codey-overflow-forum

What am I missing? I have tried to reproduce in codesandbox.io, same thing - white screen, no errors. I’m sure it is something simple, any help would be appreciated!

App.js

import React from "react";

import { comments } from "./commentData";

import Card from "./Card";

function App() {

comments.map((comment) => <Card commentObject={comment} />);

}

export default App;

Card.js

import React from 'react';
import Header from './Header';
import Body from './Body';

function Card(props) {
  return (
    <div>
      <Header profileImg={props.commentObject.profileImg} username={props.commentObject.username}/>
      <Body comment={props.commentObject.comment} />
    </div>
  )
}
export default Card;

Header.js

import React from 'react';

function Header(props) {
  return (
    <>
    <img src={props.profileImg}/>
    <h1>{props.username}</h1>
    </>
  )
}

export default Header;

Body.js

import React from 'react';

function Body(props) {

return <p>{props.comment}</p>

}

export default Body;

Argh missed return in App.js