@andrewilley
Among these unwanted tracks there are video tracks (do not show the duration) and audio tracks (do show it). I do not understand why this happens, as both the 'ignore short tracks (less than 60 seconds)' and 'ignore video tracks' options are active.
This is not a "serious" problem because I have organised playlists, but I remember that this used not to happen. I often download a song and in "recent additions" I can't find it because of these hundreds of short files that I don't want!
I would like to remind everyone that I am only and exclusively talking about what I display in 'added recent'.
Music Folders list only points to the folder containing your required music files, not to your WhatsApp cache folders .. do you know in the settings how to do it?