Dear Samsung users:
Based on your description, it is recommended that you try the following methods:
1. It is recommended to enter Settings-More- Application Manager-All-Contacts-Clear Data Try.
2. Check whether a software program such as Mobile Security Guard is installed on the phone. If so, please try to uninstall it to see if the third-party software installed is incompatible or caused by software restrictions.
3. Try using another SIM card
4. Back up the important data on the phone and try restoring the factory settings
If the problem persists, we recommend that you Send the phone to your nearest service center for testing.
It is recommended that you make an "appointment in-store" maintenance application on Samsung's official website to enjoy priority maintenance services: /pre-booking
After a successful appointment, please bring your machine, invoice and warranty Card to visit your scheduled service center on time.
If you need help, please visit support.samsung.com.cn, the official website will provide you with multi-channel service support!