Hi there,
After upgrading to iOS 18, I noticed that ApplicationMusicPlayer.Queue behavior has broken if at least one song that is added to the queue is also in to the Apple Music Library on the device.
The resulting behavior is that the queue does not accept all the items, and only items that are in the Library are playable in the queue.
The expected behavior and the previous behavior on iOS 17 was that all the items would be added to the queue successfully. I confirmed this behavior on a separate test device running iOS 17.7.
The items added are all being fetched via MusicCatalogResourceRequest<Song> so I would expect that a requested song being present in the library would have no effect.