I have the newest apple watch 7.1 with cellular. I run with the Nike app and listen to Spotify and purchased the cellular version so that I did not have to run with my phone. When I start, I choose "play on apple watch" - it will play 1 song and then stops. I check that I have a strong cellular signal which it has. It is super frustrating. I have Spotify 220.127.116.119 version.