Display error on iPhone 7

Hi

You may wish to consider trying the following steps:

• Back up your iPhone (you may wish to encrypt the backup, if using iTunes):

  How to back up your iPhone, iPad, and iPod touch - Apple Support

• Restore it to factory settings, with a fresh copy of iOS:

  Use iTunes on your Mac or PC to restore your iPhone, iPad, or iPod to factory settings - Apple Support

• Check whether the issue recurs before or after restoring from backup:

  Restore your iPhone, iPad, or iPod touch from a backup - Apple Support

If the issue persists (or if you would prefer to skip directly to this step), I suggest that you contact your carrier (if the iPhone was purchased from them), Apple Support or an Apple Authorised Service Provider with a view to having your iPhone checked and, if recommended, serviced or replaced under warranty:

• Contact - Official Apple Support
• iPhone Service Answer Center - Apple Support