Web IDE Preview just spins on Gitlab.com

For my new repo, I am trying to live preview a HTML file in the Live Preview window of the Web IDE.

Rather than rendering the content, the url bar just spins for a few seconds then nothing is displayed.

This error shows up in the console when the spinner stops -

sandbox-service-worker.js:1 Uncaught (in promise) Error: Request for https://sandpack-0-0-48.codesandbox.io/frame.html?_sw-precache=d14ea2c834e4b5e681d76fc2ec0bcd46 returned a response with status 404
    at sandbox-service-worker.js:1

Let me know if there is any more information I can provide. Thanks in advance for your help!