URL: https://www.theguardian.com/video

Browser / Version: Firefox 120.0
Operating System: Mac OS X 10.15
Tested Another Browser: Yes Safari

Problem type: Video or audio doesn't play
Description: The video or audio does not play
Steps to Reproduce:

1. Go to https://www.theguardian.com/video with Firefox Nightly without any extensions installed.
2. Try to play any videos.

Result:
The video is not playing.

An example of the messages in the console.

A resource is blocked by OpaqueResponseBlocking, please check browser console for details. 2
Failed to execute ‘postMessage’ on ‘DOMWindow’: The target origin provided (‘https://www.youtube.com’) does not match the recipient window’s origin (‘https://www.theguardian.com’).

From webcompat.com with ❤️