This applies to all my platforms (i.e. Windows/Android/Alexa
The last few days, all of my devices are greyed out so I can't play music from my Desktop app to my Alexa speakers.
Occasionally, they won't be greyed out and work fine, I'll come back 30 mins later and they're grey again. Sometimes I can play form my Android but not Windows app.
The only recent change was that my internet connection dropped last week due to all the BT issues nationally.
All devices are on the same local network (there's only one), they've all been working for 18+ months, I was listening to a playlist the other day, which inexplicably stopped and form that point I had this greyed in/out problem.
Every other devices is definitely connected to the internet, they'll happily play every other source I throw at them, it only affects Spotify. The Spotify app on each device is up to date.
Same issue this morning, all devices were available, I checked and started a playlist. Came back 30 mins later, all devices greyed out.
Nothing seems to resolve it reliably, I've uninstalled/reinstalled the app, checked the Alexa devices are all added via Spotify Connect which they are, I literally made no changes and keep getting this issue.
This isn't consistent, but just now, when I asked Alexa to play my Playlist, all the devices appeared in the Spotify app again.
Another seemingly unrelated issue, when the devices are available, I'll get "This track can't be played at the moment" again, these are tracks and playlists that have played reliably for years, and it's all tracks not just some...
It's annoying that having been so reliable for years I'm now getting these problems, with no apparent cause.