On iOS 10 or earlier, when users subscribe to a new podcast, they would always get the most recent episode downloaded to their library. Starting with iOS 11, Apple added support for two types of podcasts.
Episodic podcasts (default podcast style)
Latest episode recommended first
New subscribers receive the latest episode
Optionally supports seasons, with newest episode at top
Episodes are presented and recommended oldest-to-newest
Great for narrative and storytelling content
New subscribers will receive the first episode in their Library, or the current season if using seasons
There’s also episode types: full, trailer, and bonus content.
Full (default). An ordinary podcast episode.
Trailer. A short, promotional piece of content usually released before a new show or season.
Bonus. This is extra content for your show (for example, behind the scenes information or interviews with the cast or cross-promotional content for another show.)
You can find further information from Apple about the podcast tags for your show.
Once you've identified which style of podcast yours is, take these steps to update your podcast in Omny Studio.
If you have an episodic podcast, you don't need to change your playlist since that is already the default as seen here under Playlist details > Optional podcast metadata > Podcast type
Optionally, if you wish to add season or episode numbers to your episodes, you can do so by editing the clip, adding season and episode numbers, and episode type.
In the playlist details page, expand the "Optional podcast metadata" section, and for the "Podcast type" dropdown select "Serial".
Add season and episode numbers to your episodes in the clip details page under the "Optional metadata" section. You can only number your seasons and episodes with a number (cannot use letters or symbols).
Then you're done. Your podcast will display seasons and episode numbers in the Apple Podcast app.
Omny allows your season and episode numbers to be applied to your podcast for distribution to podcast apps other than Apple Podcasts (which don't use the Season and Episode tags), read more here.