If you have updated your RSS URL in Apple Podcasts Connect or added the <itunes:new-feed-url> tag to your RSS feed, then Castbox will automatically reflect this change.
We will create a new Castbox channel using your new RSS feed and the old channel will be unpublished. The subscriber and play numbers will be be synced to the published channel. If you claimed the old channel already, the status in Creator Studio will update after 24 hours. If you search your podcast on Castbox, only the published channel will show up in the search results.
For existing subscribers of all old/duplicate channels, as long as the channel is still playing and updating fine as the published channel does, they can still see the original channel they subscribed to. Otherwise, the subscribers will see the notification leading to the published channel. For all future subscribers, they will only see the published channel when they search the podcast.
An example of hidden/unpublished channel with a notification bar is shown below.