x0 is generating nested anchor tags from md to html.

you can replicate by creating a md file with a h1:

// hello.md
# Hello world

And render this

// index.js
import React from 'react';
import Hello from "./hello.md";

export default class extends React.Component {
  render() {
    return Hello />
  }
}

Also happening on https://mdxjs.com

It doesn't happen on the x0 docs site though, maybe this was introduced in a later version?

Thanks!