Rekordbox App to manage library

I use tag to sort my music in intelligent Playlist. When i go to a Playlist in the app and then remove the tag that placed the song in that Playlist, the song won't disappear from that Playlist in the app. It syncs to the computer and disappear from that Playlist. But in the app it's still in the Playlist. Why? I would really like a good track management app for sorting music easy on the fly with my mobile.