Your picture with the green question marks is whether you want to make your playlist public. You know that. Public means that others can listen to your playlist in Qobuz or Tidal. You can also make friends, but that’s another topic.
You did everything right.
Your 39 songs from Qobuz, that’s where you created the playlist.
The only explanation I can think of is that you were on another streaming service and added 1 song from Tidal or your own music to the 39 Qobuz songs, for example, and the Qobuz playlist became an all-playlist. That’s what happened to me too.
Then of course only the Qobuz songs are synchronized.
Just like I typed it above. It’s logical! You can’t add songs from other people to, let’s say, the original Qobuz playlist, whether in RoseApp Qobuz or the original app. That’s why there are always two playlists (see post above)
I’ll repeat myself: I know that you know all this, including that you already have all playlists.
What do you want to convert the playlist into??? I don’t quite understand!
That didn’t help you much here, I can’t explain it very well.
…and if by converting you mean that the 39 songs from Qobuz should become a Qobuz playlist again…
…create a new playlist (same name and put a 1 at the end so you don’t get confused at first). Open the All Qobuz playlist (35 titles) and add everything to the newly created playlist. You know how to do that. Then delete the Qobuz All playlist and rename the new one. In this example, you only need to delete the 1 at the end. Then you have an official Qobuz playlist.