2 x Rasberry pi with Hifiberrios usage with spotify

Hi I use two Raspberry Pi3 with Hiffiberrios software to connect audio devices with roon. It is working perfect.
Time to time I will use it with Spotify, but using this connection it is not possible to connect directly on or another, it is like random and it is connecting with one of both.
Which solution would you suggest ?
Best regards
Marian