I'm having this same problem, when I'm playing from a playlist folder on Mac, if I then cast to my smart tv it will finish playing the current song and then give me an error that Spotify is unable to play the next song. If I try playing the playlist folder from my Mac again, while casting to a speaker or smart TV, it gives me the same error. If I'm just playing an individual playlist it plays normally while casting to another device. See attached screenshot. Is it possible to get the same instructions as above but for M1 mac? Is this a bug or just another feature Spotify is inexplicably retiring without notice??? At the very least I would like notification from Spotify that this feature is being retired if I'm going to continue paying for this service.