My playlists are gone
Check that you are signed in to the app using the same account that was used to create the playlist. To do this, go to your portrait in the upper-right corner. The username for the current account will appear.
If certain tracks in the playlist are grayed out and you can't listen to them, it means that the period of the license agreement between the individual who holds the rights to the track and Yandex.Music has expired.
If the playlists don't appear even if you are using the correct account and your devices have synced, write to customer support.