This is because the music starts automatically. Just turn it off. Here, take the OPPO R9S mobile phone as an example. The specific methods are as follows:

First, click the "mobile phone housekeeper" icon on the mobile phone desktop, as shown in the figure.

second, select the "privilege privacy" option in the mobile phone housekeeper interface, as shown in the figure.

third, open "self-startup management" in the permission privacy interface, as shown in the figure.

fourth, find the application for playing music after entering. Take Netease Cloud Music as an example, just turn it off.