Hi tah800
Sorry to hear that you are finding the app difficult.
There are sections in the online manual to cover most things here: https://luminmusic.com/manual
A good starting point for what you describe above is here:
https://luminmusic.com/manual/app-introduction.html
The main thing to know is that LUMIN will only play tracks from its own playlist.
This is the list shown on the left on tablet, or in the middle screen on phone.
If something is playing on LUMIN, then it has been added to this playlist.
The icons at the bottom of it let you save, load and delete these LUMIN Playlists.
To get things into the playlist, you need to use the browse window first. Selecting them will move them into the Playlist. Depending on your settings, there are different ways that tracks move across. Some people requested that adding a track also adds the whole album, so there are options for that, as well as selecting multiple tracks. This is explained in more detail halfway down this page:
https://luminmusic.com/manual/app-browsing.html
If you use TIDAL playlists as your primary music organisation method, then you might prefer using TIDAL Connect (if you have a more recent LUMIN Model). It really depends if you also use locally stored music, or other streaming services and want to mix playlists.
If not using TIDAL Connect, read on.
You can add a whole TIDAL playlist to your LUMIN Playlist from within the app by browsing TIDAL > My Music > Playlists.
Then you can press and hold on the whole playlist to add it to the LUMIN Playlist.
Depending on which button you press it will add to the end/current position or replace the whole playlist.
The button icons are described on that link above too.
What isn't possible is that when you add tracks to a playlist in TIDAL, it will automatically add them to the LUMIN one - you'd have to navigate to and press and hold the playlist again.
For details on how to save/load playlists see here:
https://luminmusic.com/manual/app-playlist.html
The only thing I wasn't sure on was why a playlist might have disappeared. But perhaps it was just confusion between seeing the browse window and seeing the playlist window. As mentioned in the manual, getting an overview of the app is best done on tablet if possible.
I hope that's helped a bit, but hopefully a good read of the manual will help further.
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