Windows 8.1 audio not playing in background

Question

I'm developing the app that plays music in foreground and background in Windows 8.1. I have done all as per msdn article: How to play audio in the background

• declared background audio task
• added MediaElement to the page with AudioCategory="BackgroundCapableMedia"
• subscribed to SystemMediaTransportControls events

Audio starts playing, but when I press Start button, audio pauses until I reopen the app

I have tried msdn sample, but it also stops playing when I press Start button - Stream Online Audio and Play in Background Windows 8.1