New RSS Feed Not Picked Up By Podcast Platforms

I recently refreshed our website with a new theme.
As part of the refresh we moved to using Powerpress to create our RSS feed for podcast platforms.
I have used Powerpress before on another site without any issues.

Because Powerpress creates the RSS feed differently to our previous method, it means a new URL is in use.
As per previous Powerpress support for another site, I have used the “Redirection” plugin to set up a divert from the old RSS URL to the new.
However, none of the podcast platforms have picked this up and now our podcast is not shown on any of them.

The feed itself is good and I have validated it using the Cast Feed Validator.

Any idea why the redirect is not working?

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