My problem seems to be with Chrome and NOT my code

I am trying to get the Player Component to render. I am running Chrome Version 72.0.3626.96 (Official Build) (64-bit) on a Mac with Mojave.

Here is my app.js file:

const Header = () => {
    return (
        <header>
            <h1>Scoreboard</h1>
            <span className="stats">Players: 1</span>
        </header>
    );
}

const Player = () => {
    return (
        <div className="player">
            <span className="player-name">
                Doug
            </span>
            <div className="counter">
                <button className="counter-action decrement"> - </button>
                <span className="counter-score">35</span>
                <button className="counter-action increment"> + </button>
            </div>
        </div>
    );
}

ReactDOM.render(
    <Player />,
    document.getElementById('root')
);

Here are the things I have tried:

1. Running in Chrome Incognito -- things run brilliantly
2. Running in Safari -- things run brilliantly
3. Running in Firefox -- things run brilliantly
4. Running in Chrome (vanilla) -- only the Header Component will render, no matter which component is present in the ReactDOM.render()
5. Firing up the server this way: python3 -m http.server -- see items 1-4
6. Firing up the server this way: python3 -m http.server 8080 -- see items 1-4
7. Changing the render back and forth between Header and Player -- see items 1-4

Clearly my code is working except in vanilla Chrome. In all cases I have used the developer tools to see what is going on with the elements. In all cases, the root div (except vanilla Chrome) is updated properly and the components render properly. I have stripped Chrome of all extensions and I have re-downloaded and re-installed it. There should be nothing mucking up the works.

But clearly there is.

Any ideas?