Apple Music API: Adding To Collaborative playlist gives 500 error

I am using https://developer.apple.com/documentation/applemusicapi/add-tracks-to-a-library-playlist to add tracks to playlists. This endpoint works fine for all playlists except for collaborative playlists. For collaborative playlist I get the following 500 error as a response:

    "errors": [
        {
            "id": "<some id>",
            "title": "Upstream Service Error",
            "detail": "Unable to update tracks",
            "status": "500",
            "code": "50001"
        }
    ]
}

Steps to reproduce:

1. Create a playlist in your library.
2. Use the api to add a song.
3. Confirm that it works.
4. Make that same playlist collaborative.
5. Update the playlist ID in your api request (as making a playlist collaborative changes its id)
6. Confirm that you get the 500 error.