djpro2 : songs removed from playlists

I have been importing a lot of playlists from spotify to mylibrary.

Finally I thought that I’ve managed to grab them all, but then I started to play and noticed that my playlists doesn’t anymore contain same amount of tracks what’s were initially imported.

This is gonna be hard to reproduce, but now I’m deleted all my playlists and regenerating them all.

Any hints where to look at or what might cause the issue that songs are removed from playlist?

On the otherhand I have another issue, can’t remove songs from playlists, but whole playlist can be removed…