YouTube HTML5 issue

Description of the issue:
I get a YouTube error when trying to watch a movie I purchased:
“Your browser does not currently recognize any of the video formats available.
Click here to visit our frequently asked questions about HTML5 video.

Exact URL of the website in question: https://www.youtube.com/watch?v=tgKhPObZeaw

Did the issue present with [default Shields settings]?: Yes

Does the site function as expected when Shields are turned off?: Does not make a difference.

Does the site work as expected when using Chrome: Yes

Brave version: 1.4.96

What operating system are you using?

I’m on macOS 10.14.6