Based on the situation of your mobile phone, it is recommended to try the following methods to solve the problem:

1. It may be a pop-up caused by the third-party software you installed. You can first determine what software it is, and uninstall.

2. Enter the phone settings--system upgrade to download and install the latest system version.

3. Enter the phone settings--more settings--restore factory settings--restore all settings. This operation will not lose data.