Restart the phone
Try to restart the phone to see if the problem is solved. Sometimes, a simple restart can solve many small problems!
Update system version
If the problem persists after restarting, please consider updating your mobile phone system version. However, please note that important data in the device, such as contacts, text messages and photos, must be backed up before upgrading.
Restore factory settings
If you try the above two steps, but the problem still exists, you may need to restore the factory settings. But again, remember to back up the data in advance!
Seek professional help
If all the above methods have been tried and the problem still exists, then you may need to go to the local Samsung after-sales service center. Remember to bring your mobile phone, purchase invoice and maintenance card, and let professional engineers check it for you.