There are lots of podcast directories trying to read your RSS feed - not just Apple Podcasts. Just like your website needs to be browser compatible, your podcast feed needs to be compatible with services that read podcast RSS feeds.
Most podcast feed-readers are not as forgiving as Apple. If your feed can’t be read, it will most likely get skipped and not included in other podcast apps and sites.
We’ll tell you what’s wrong with the feed, it’s your responsibility to fix any problems. Even warnings can cause problems for readers. Podcast feeds have more requirements than a traditional RSS feed, and with Cast Feed Validator, we’re checking all of those for you.