Solution:
When Mi TV and box uses some music software to play music, it can only play when the software is running in the foreground. After pressing the HOME button to exit, the music stops and cannot be played in the background. This is because some software does not have the function to play in the background, or the function of playing in the background is turned off.
Background player is turned off by default. If needing the software to play in the background, the setting steps are as follows: open App -> and select the setting in the upper right corner -> player option -> to set "background player" on.
Notes:
If you want the music app to play in the background, please press the HOME button to exit. If you press the Back button to exit, the concert will stop. If the music is played at the same time as the video, the music may pause.