Hello, following the subject here closed : 

I would like to add my experience has I found one specific reason to that. I had the exact same problem using a playlist on Spotify. I tried everything related to a network or device issue as described on the original article, but none solved the problem.

Googling to know wether other people had this problem, I found one which led me to the solution : it was a playlist size issue. Indeed I noticed I didn’t have the problem listening to music on Apple Music service. Actually the playlist I was listening to had 4652 titles for a total duration of near 250 hours !
Too much it seems for the Sonos app.

It would be interesting to know how much titles the app can handle on a single playlist.
Want to reproduce the problem ? The playlist is “Cinemix Radio official playlist” by Chris Vuillard.
 

Using any other (shorter) playlist, everything is working perfectly good.