Player won’t load audio file, getting 404

Hi! Trying to get the audio player to work on the following podcast episode:
https://thisweekinwp.wpengine.com/podcast/week-15-2021/

I noticed that the file the audio player tries to load is returning a 404:
[audio src="https://thisweekinwp.wpengine.com/podcast-player/33/week-15-2021.mp3" /]

But the episode itself does contain the correct mp3, which loads without any problems:
[audio src="http://thisweekinwp.wpengine.com/wp-content/uploads/2021/04/2021-15.mp3" /]

Note that I’m using the TT1 Blocks theme with the Site Editor – but I’ve tried with plain old Twenty Twenty-One, and the same problem occurs.

Also note, the episode is encoded with chapter notes and artwork, done using Forecast by Overcast: https://overcast.fm/forecast

The page I need help with: [log in to see the link]