Spotify Connect Desktop & Android

[Therealbeda]

Hi everybody,

First of all, english is not my first language, failures may happen.

My Problem:

Most of the time I'm using my desktop as remote to control my Android which is connected to Bose Soundlink II via Bluetooth. After a minute of listening to music the display of my android switches to black while Spotify is still running and Spotify switches from Android to Desktop. Now I have to open Spotify on my Android manually and switch it back which is very annoying. 

Does anybody have an idea what is the problem?

Thanks in advance.

therealbeda