Spotcast issue Google mini

Hi all,
someone can help me with the following issue?
I’ve installed and configured spotcast to be able to reproduce Spotify music on google mini device.
After a lot of attempts, I’ve found that the correct configuration for me is:

service: spotcast.start
data:
  spotify_device_id: xxxxx
  uri: 'spotify:playlist:xxxxxx'

The problem is that it’s working just once in a while…a lot of time I receive this message error:

2021-04-07 15:56:02 ERROR (SyncWorker_17) [spotipy.client] HTTP Error for PUT to https://api.spotify.com/v1/me/player/play?device_id=xxxxx returned 404 due to Device not found

2021-04-07 15:56:02 ERROR (MainThread) [homeassistant.components.websocket_api.http.connection] [1737387864] http status: 404, code:-1 - https://api.spotify.com/v1/me/player/play?device_id=xxxxxxx:

Device not found, reason: None

How can I solve it?
Thanks!