Thanks, reproduced, fixed as https://www.ventismedia.com/mantis/view.php?id=15413

Yes, track disappears from playlist.

I"m new to MM, so am not familiar with terms well.
The playlist that I'm refering to is one of the default ones that is created by MM itself. Media tree/Musics/Years/2019 (for instance). (MM has catagorised tracks by decades/years automatically)

For 2019 playlist, change view to "List view" or "Album & Tracks", now if you play a track, it will disappears and the number of files decreases.

What do you mean by "track is hidden" ?
Are you saying that once you play the track then it disappears from playlist?
Is it auto-playlist or static playlist? Or do you mean "Now Playing" playlist?

I've noticed that in default playlists organised by years, 2019 for instance, the track is hidden when I play manually the track or when it reaches the end. The number of files at the bottom corner is decreased then.Of course, in the list view layout or Album and Tracks view.