Delete the alarm. Then remove Spotify from your music services in the Sonos app and re-add it. Then set the alarm again.

Ok, so I did that : delete the alarm, remove Spotify, re-add it, reset the alarm.

Now, it never works the first time : the alarm rings with Sonos chime but if I snooze (with "repeat in 5 min" option activated) then it works the second time everytime. I don't understand why, what should I do ? When is the best time to make a diagnostic for you guys to see the problem ?

Also, I realise that the alarm works without problem with a shorter playlist or an album but why ?

Thanks for your help

I’m experiencing the same problem and recently was able to reproduce the problem.

I have a setup with Spotify Premium and each family member has their own Spotify account. The alarm uses my account and an official Spotify playlist. Most often we are listening to music on the Sonos system with my Spotify account and the alarm the next morning works fine, playing the selected playlist.

Whenever my children starts playing music on the Sonos system, starting from Spotify on Android phone the problem with the alarm is present. The next morning the alarm uses the chime signal instead.

As long as I’ve played music from the same Spotify account as the alarm is set to use everything is working. The problem seems to be that Sonos fails to switch Spotify account when starting the alarm and then reverts back to the chime signal.