Spotify continues to play music during incoming call

[AyakliGoogle]

I've got a strange problem. Sometimes when I was listening music on Spotify, if I get an incoming call, song doesn't stops. And sometimes when I close the app, it continues to play songs for a minute or so. App doesn't actually closes. I don't know whether the problem is from Spotify or Sony. At this picture, even though I closed the app, Spotify still plays the song. Anyone experiencing same problem ?

[Uliwooly]

Indeed closing the app using the task manager won't stop the music, you have to pull down the notification and pause the music.