IMDB Lists and Auto Download

I created a public IMDB list (not watchlist), added a movie to it. Added the list to RADARR. And then told radarr to scan the list. It worked. Then today remotely, I added movies to that list, but nothing is downloading. How do you set up radarr to monitor the list for changes, and start the downloads? Or does it have to be your IMDB watchlist? Sorry for what is probably a commonly asked question. Most of the posts talked about watchlists, so I thougt maybe it was different.