OPPO phones always ring for no reason, just like a message.

OPPO mobile phone suddenly appears prompt tone, which may have the following situations: software prompt tone, such as the information prompt tone of third-party software advertisements or pushes such as QQ and WeChat, and it is recommended to turn off the prompt tone in the corresponding software.

Cell phones always ring for no reason. This is a message notification from some third-party software, but because the system intercepted the harassment of these messages, you only heard the prompt tone and didn't see the prompt information.

This answer applies to all OPPO models.