You would like to use the sleep timer with Spotify Connect. However, when you want to set this up, the message "Sorry, the power on function is not available for Spotify Singleroom mode" appears?
First, activate the Spotify Multiroom mode. If you have only one device or want to use only one device with the sleep function, select only one player for the Spotify Connect Zone. Then you can use the sleep-in function as usual.