You can't use a regular RSS feed validator to check a podcast feed for errors. Sites like "W3C Feed Validation Service" and "feedvalidator.org" were designed to validate RSS feed for blogs, not podcasts.
Instead, you should [Podbase](https://podba.se/validate/)
It will give you a report that looks like this:
Instead, you should [Podbase](https://podba.se/validate/)
It will give you a report that looks like this: