Cant add songs from Collection or Existing Playlist to another playlist

Hi!

Im using the latest version of RekordBox 6.5.3.

When in my Collection or any existing playlist I try to add song to a new playlist they just dont appear in the new one.
No exclamation marks, and error messages. Simply the new playlist doesnt show any songs.
I can import songs to rekordbox with no problems. The program analysis the song correctly and all. But they stay in the Collection and dont show up in the playlist I imported them.

Any help?

I already send message to PioneerDJ but still they didnt give me a solution. 

Thanks!