To play via Spotify connect you must have a Spotify Premium account

Please try the following :

Within the Spotify app Home>Settings>Devices ....Show local devices only make this green slide to the right to turn on

1. Download the latest firmware/Software
2. Clear the Spotify Cache;  Settings Menu / Storage (Delete cache) 
3. Close down other apps you're not using 
4. Restart your device 
5. Restart your WiFi Router  (turn off 30 seconds and turn on)