I'm really confused why I can call /search/multi, get an ID of one of the items returned, take that ID and call /tv/{series_id} one day and get the same item, and then call /tv/{series_id} again the next day and get a totally different item. Why wouldn't you have unique IDs for items? How else do API consumers know what series_id to use?!

I understand duplicate items getting removed, but are the IDs for those items really recycled? If so, how can you ever know what ID to use for /tv and /movie endpoints?