We have a very specific situation: one of our apps has several extensions added to it, but we didn't create specific App IDs for them because we use a wildcard ID (*). We also used multiple different app prefixes for historical reasons, and therefore have multiple wildcard IDs with different prefixes.
This has worked fine for some time, but now the old distribution certificate has expired and when we made a new one, xcode automatic signing generates a profile for the wrong prefix (it matches a wrong wildcard ID) and creates an ID with this wrong prefix for the extensions.
To get around this, we tried manually adding complete apple IDs for all the extensions on the dev portal, however one of those keeps getting refused saying that it already exists.
Since we already have an application published on the App store with that same extension, it couldn't have possibly been taken by anyone else.
So to recap: automatic signing assigns the wrong prefix and we can't register the ID manually, so we are forced to publish the app with the changed extension ID prefix which is less than ideal obviously. Is there a way around this?