useEffect with empty dependency array runs twice

I'm learning React following an Udemy course. Instructor said that useEffect with empty depends array should runs only once (on mount), but I'm seeing two logs in my console with this simple code:

import { useEffect } from "react";

export default function App() {
  useEffect(() => {
    console.log("Should run one time");
  }, []);
  return <div>Hello World</div>;
}

Is there something I missed here?