This situation is normal. Because the game has sound and will be occupied, you only need to start the game and then turn on the music again, so that you can play songs while playing the game. Take Apple 13 as an example:

1. Slide the lower bar up to open the background running program.

2. Click Music.

3. Click play. The music will not be turned off when you return to the game.

4. Or exit the game background and directly slide down the upper right corner bar to open the control center and click to play music.