Hello @Stefano_Sartori,
Thanks for contacting support, I’d be happy to take a look over the issue you are facing here. When you mention that the playlists are empty, are you browsing them in Roon or through the TIDAL app? Can you please provide a screenshot of what the TIDAL playlist looks like in Roon vs what it looks like through the TIDAL app? Can you provide some more information about your setup using this link as a guide? I look forward to hearing you reply!
Thanks,
Noris