Sounds mute in unity-made game when sound from any other app plays.

I am using Unity 5.4.0b10 and I made a game using it and ported it to android.
It runs fine in my device and in normal condition the sfx works fine.

But if I, say, run a music player in a background, or say, a notification sound plays in the background due to some incoming message, then the sound stops playing in the unity game…and the only way to make it work again is to restart the game.

Any idea why this can be happening?

“Android: Mute audio if audio focus is lost” is a bug on Unity 5.4.0b10.

Its fixed on Unity 5.4.0b11

Reference:
https://unity3d.com/unity/beta/unity5.4.0b11

i got the problem on 5.3.5 also

Must have been fixed before but is broken for us at least in 2018.3 again