Kawara Tsutomu Customs has been sending messages in the background.

The text messages sent by the fee are all free text messages, which don't cost you money. SMS mute duration is used to block reconciliation SMS. You can try to adjust your tone. Their default value is 30. If you can't see it, try adjusting it later. Then there must be other software installed in your mobile phone, such as 360, and there will be software conflicts. I met them on my mobile phone before, and I asked them if it was a software conflict. Later, it was okay to uninstall 360, but it was also related to mobile phones.