RSS feed validated manually, but iTunes still rejects

Hi all – I was wondering if anyone has run into this issue. I have validated my feed URL through two different validating services as well as manually submitting the URL to iTunes and on mobile through the Podcast app. Everything works fine until I submit it to iTunes – they reject the feed. The answer I got from iTunes was:
“We detected a technical issue when attempting to fetch content from your RSS feed. This is typically caused by server availability issues with your hosting provider. Please contact them to ensure that your show’s episodes and artwork are always available.”

Here’s the feed that Sermon Manager gives me under the “podcasts” tab in settings: https://www.stalbanswaco.org/?feed=rss2&post_type=wpfc_sermon

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