Player won't play unless stays on screenscreen with Nexus 6

Hi- I have a Nexus 6, Lollipop 5.1 OS. Using the Xiia Android app all works fine as long as the player stays on screen. When the screen goes off or if I am doing other things on the phone the stream plays a few seconds, then goes off and then tries to reconnect, max tries reached, etc. All I have to do is bring it down from status bar to open on screen, click play and it immediately works fine. Suggestions? I LOVE Xiia, so I am going nowhere... Just wondered if this can be fixed soon. Thanks- Amanda