Name greyed in iPhone settings

First try closing all open apps: Close an app on your iPhone or iPod touch - Apple Support and then force restart: Force restart iPhone - Apple Support

Then update iOS to the most current for your iPhone: Update your iPhone, iPad, or iPod touch - Apple Support.

Then verify that Screen Time was not enabled, or that related restrictions within Screen Time were not enabled: Use parental controls on your child's iPhone, iPad, and iPod touch - Apple Support.

If that all fails, you’re headed for a discussion with Apple Support.