Apple Podcasts feed shows only a fraction of episodes after domain change

When you have a query of this sort you need to post both the Apple Podcasts Preview page URL and the feed URL. Without being able to read the feed it's not possible to do forensic analysis.

What I can tell you is that while the Preview page and the Podcasts App on a Mac show only two episodes for this year, both from last Tuesday, subscribing on a Mac (which reads the feed directly) shows a large number of episodes (I think 26), plus many from previous years.

So Apple Podcasts itself (what used to be the iTunes Store) is failing to read all those extra episodes from this year. (It does show some from previous years).

A GUID error would effect both readings; basically if two episodes have the same GUID the later one will be ignored. This doesn't seem to be the case here.

GUIDs must be unique, not only to your podcast but to everyone else's, so it's common practice to use the episodes URL as obviously this must be unique. Transferring the feed to a different URL might cause the GUIDs to be re-written automatically, which should cause every episode to show. Even it they weren't any problem would probably affect every episode.

You should check the feed, looking at the GUIDs for the missing episodes this year and see whether there is anything odd about them. (Any actual error of the sort that can cause problems, such as curly quotes, would have been cauught by the validator.

You could try contacting Podcasts Support and ask them to reefresh the feed:

https://itunespartner.apple.com/contact/?content_type=podcasts

Comparing the coding for the two recent episodes, which show, with the preceding one, which doesn't, there isn't anything which would explain this. the GUID tags follow the same format.

Of course, I can't look at what the GUID tags were on the old feed, nor indeed confirm that Apple are actually using the new feed (since they don't provide a way of checking the feed URL). However I assume you would know if the changeover had not happened.

The GUID tags have changed from the old feed, since they use the afteramherst.com domain, but as this is the same in both the visible and invisible episodes this doesn't seem to be relevant.

So I can't give you an explanation, and can onlytsuggest asking Podcasts Support to refresh the feed.