mobile

hello z2 users!!.
recently i bought my z2 in replacement with my old N7000 note1. i used my note 1 in recording video of myself playing guitar and at the same time playing MP3 backing track on the same phone. i have tried that features on other phone like lenovo and its working fine. i like this kind of feature where in our phone is a multi task.

when i test it to my Z2. play the music on the walkman app, minimize open the video camera. and start recording suddenly the music stops. i tried the other way around, open camera app, start video recording, it stop upon minimizing the camera app.

Now my question is:
1. is this a common issue of Z2? is it normal on sony phones.
2. is there a way that my phone can use this feature?

i hope i get reply on my queries as i am hoping to use the phone like this