I am a Spotify premium user and have been streaming via two Google Chromecast Audios successfully for at least a year. Recently connection to the Chromecasts has become more difficult as they do not always appear in the Devices Available list on the Android app. The non-appearance in the list now seems to be normal, meaning of course that I can't use Spotify on the Chromecasts from my phone without a great deal of workaround e.g. restarting the phone, rebooting the Chromecasts, removing and reinstalling the Chromecasts on my home WiFi network. Once connected Spotify mostly works successfully, with the server updating the app as one music track finishes and the next starts, but sometimes the app does not show these updates and control of the music stream from the phone becomes impossible.